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diff --git a/Documentation/admin-guide/LSM/index.rst b/Documentation/admin-guide/LSM/index.rst index a6ba95fbaa9f..ce63be6d64ad 100644 --- a/Documentation/admin-guide/LSM/index.rst +++ b/Documentation/admin-guide/LSM/index.rst @@ -47,3 +47,4 @@ subdirectories. tomoyo Yama SafeSetID + ipe diff --git a/Documentation/admin-guide/LSM/ipe.rst b/Documentation/admin-guide/LSM/ipe.rst new file mode 100644 index 000000000000..f38e641df0e9 --- /dev/null +++ b/Documentation/admin-guide/LSM/ipe.rst @@ -0,0 +1,790 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Integrity Policy Enforcement (IPE) +================================== + +.. NOTE:: + + This is the documentation for admins, system builders, or individuals + attempting to use IPE. If you're looking for more developer-focused + documentation about IPE please see :doc:`the design docs </security/ipe>`. + +Overview +-------- + +Integrity Policy Enforcement (IPE) is a Linux Security Module that takes a +complementary approach to access control. Unlike traditional access control +mechanisms that rely on labels and paths for decision-making, IPE focuses +on the immutable security properties inherent to system components. These +properties are fundamental attributes or features of a system component +that cannot be altered, ensuring a consistent and reliable basis for +security decisions. + +To elaborate, in the context of IPE, system components primarily refer to +files or the devices these files reside on. However, this is just a +starting point. The concept of system components is flexible and can be +extended to include new elements as the system evolves. The immutable +properties include the origin of a file, which remains constant and +unchangeable over time. For example, IPE policies can be crafted to trust +files originating from the initramfs. Since initramfs is typically verified +by the bootloader, its files are deemed trustworthy; "file is from +initramfs" becomes an immutable property under IPE's consideration. + +The immutable property concept extends to the security features enabled on +a file's origin, such as dm-verity or fs-verity, which provide a layer of +integrity and trust. For example, IPE allows the definition of policies +that trust files from a dm-verity protected device. dm-verity ensures the +integrity of an entire device by providing a verifiable and immutable state +of its contents. Similarly, fs-verity offers filesystem-level integrity +checks, allowing IPE to enforce policies that trust files protected by +fs-verity. These two features cannot be turned off once established, so +they are considered immutable properties. These examples demonstrate how +IPE leverages immutable properties, such as a file's origin and its +integrity protection mechanisms, to make access control decisions. + +For the IPE policy, specifically, it grants the ability to enforce +stringent access controls by assessing security properties against +reference values defined within the policy. This assessment can be based on +the existence of a security property (e.g., verifying if a file originates +from initramfs) or evaluating the internal state of an immutable security +property. The latter includes checking the roothash of a dm-verity +protected device, determining whether dm-verity possesses a valid +signature, assessing the digest of a fs-verity protected file, or +determining whether fs-verity possesses a valid built-in signature. This +nuanced approach to policy enforcement enables a highly secure and +customizable system defense mechanism, tailored to specific security +requirements and trust models. + +To enable IPE, ensure that ``CONFIG_SECURITY_IPE`` (under +:menuselection:`Security -> Integrity Policy Enforcement (IPE)`) config +option is enabled. + +Use Cases +--------- + +IPE works best in fixed-function devices: devices in which their purpose +is clearly defined and not supposed to be changed (e.g. network firewall +device in a data center, an IoT device, etcetera), where all software and +configuration is built and provisioned by the system owner. + +IPE is a long-way off for use in general-purpose computing: the Linux +community as a whole tends to follow a decentralized trust model (known as +the web of trust), which IPE has no support for it yet. Instead, IPE +supports PKI (public key infrastructure), which generally designates a +set of trusted entities that provide a measure of absolute trust. + +Additionally, while most packages are signed today, the files inside +the packages (for instance, the executables), tend to be unsigned. This +makes it difficult to utilize IPE in systems where a package manager is +expected to be functional, without major changes to the package manager +and ecosystem behind it. + +The digest_cache LSM [#digest_cache_lsm]_ is a system that when combined with IPE, +could be used to enable and support general-purpose computing use cases. + +Known Limitations +----------------- + +IPE cannot verify the integrity of anonymous executable memory, such as +the trampolines created by gcc closures and libffi (<3.4.2), or JIT'd code. +Unfortunately, as this is dynamically generated code, there is no way +for IPE to ensure the integrity of this code to form a trust basis. + +IPE cannot verify the integrity of programs written in interpreted +languages when these scripts are invoked by passing these program files +to the interpreter. This is because the way interpreters execute these +files; the scripts themselves are not evaluated as executable code +through one of IPE's hooks, but they are merely text files that are read +(as opposed to compiled executables) [#interpreters]_. + +Threat Model +------------ + +IPE specifically targets the risk of tampering with user-space executable +code after the kernel has initially booted, including the kernel modules +loaded from userspace via ``modprobe`` or ``insmod``. + +To illustrate, consider a scenario where an untrusted binary, possibly +malicious, is downloaded along with all necessary dependencies, including a +loader and libc. The primary function of IPE in this context is to prevent +the execution of such binaries and their dependencies. + +IPE achieves this by verifying the integrity and authenticity of all +executable code before allowing them to run. It conducts a thorough +check to ensure that the code's integrity is intact and that they match an +authorized reference value (digest, signature, etc) as per the defined +policy. If a binary does not pass this verification process, either +because its integrity has been compromised or it does not meet the +authorization criteria, IPE will deny its execution. Additionally, IPE +generates audit logs which may be utilized to detect and analyze failures +resulting from policy violation. + +Tampering threat scenarios include modification or replacement of +executable code by a range of actors including: + +- Actors with physical access to the hardware +- Actors with local network access to the system +- Actors with access to the deployment system +- Compromised internal systems under external control +- Malicious end users of the system +- Compromised end users of the system +- Remote (external) compromise of the system + +IPE does not mitigate threats arising from malicious but authorized +developers (with access to a signing certificate), or compromised +developer tools used by them (i.e. return-oriented programming attacks). +Additionally, IPE draws hard security boundary between userspace and +kernelspace. As a result, kernel-level exploits are considered outside +the scope of IPE and mitigation is left to other mechanisms. + +Policy +------ + +IPE policy is a plain-text [#devdoc]_ policy composed of multiple statements +over several lines. There is one required line, at the top of the +policy, indicating the policy name, and the policy version, for +instance:: + + policy_name=Ex_Policy policy_version=0.0.0 + +The policy name is a unique key identifying this policy in a human +readable name. This is used to create nodes under securityfs as well as +uniquely identify policies to deploy new policies vs update existing +policies. + +The policy version indicates the current version of the policy (NOT the +policy syntax version). This is used to prevent rollback of policy to +potentially insecure previous versions of the policy. + +The next portion of IPE policy are rules. Rules are formed by key=value +pairs, known as properties. IPE rules require two properties: ``action``, +which determines what IPE does when it encounters a match against the +rule, and ``op``, which determines when the rule should be evaluated. +The ordering is significant, a rule must start with ``op``, and end with +``action``. Thus, a minimal rule is:: + + op=EXECUTE action=ALLOW + +This example will allow any execution. Additional properties are used to +assess immutable security properties about the files being evaluated. +These properties are intended to be descriptions of systems within the +kernel that can provide a measure of integrity verification, such that IPE +can determine the trust of the resource based on the value of the property. + +Rules are evaluated top-to-bottom. As a result, any revocation rules, +or denies should be placed early in the file to ensure that these rules +are evaluated before a rule with ``action=ALLOW``. + +IPE policy supports comments. The character '#' will function as a +comment, ignoring all characters to the right of '#' until the newline. + +The default behavior of IPE evaluations can also be expressed in policy, +through the ``DEFAULT`` statement. This can be done at a global level, +or a per-operation level:: + + # Global + DEFAULT action=ALLOW + + # Operation Specific + DEFAULT op=EXECUTE action=ALLOW + +A default must be set for all known operations in IPE. If you want to +preserve older policies being compatible with newer kernels that can introduce +new operations, set a global default of ``ALLOW``, then override the +defaults on a per-operation basis (as above). + +With configurable policy-based LSMs, there's several issues with +enforcing the configurable policies at startup, around reading and +parsing the policy: + +1. The kernel *should* not read files from userspace, so directly reading + the policy file is prohibited. +2. The kernel command line has a character limit, and one kernel module + should not reserve the entire character limit for its own + configuration. +3. There are various boot loaders in the kernel ecosystem, so handing + off a memory block would be costly to maintain. + +As a result, IPE has addressed this problem through a concept of a "boot +policy". A boot policy is a minimal policy which is compiled into the +kernel. This policy is intended to get the system to a state where +userspace is set up and ready to receive commands, at which point a more +complex policy can be deployed via securityfs. The boot policy can be +specified via ``SECURITY_IPE_BOOT_POLICY`` config option, which accepts +a path to a plain-text version of the IPE policy to apply. This policy +will be compiled into the kernel. If not specified, IPE will be disabled +until a policy is deployed and activated through securityfs. + +Deploying Policies +~~~~~~~~~~~~~~~~~~ + +Policies can be deployed from userspace through securityfs. These policies +are signed through the PKCS#7 message format to enforce some level of +authorization of the policies (prohibiting an attacker from gaining +unconstrained root, and deploying an "allow all" policy). These +policies must be signed by a certificate that chains to the +``SYSTEM_TRUSTED_KEYRING``. With openssl, the policy can be signed by:: + + openssl smime -sign \ + -in "$MY_POLICY" \ + -signer "$MY_CERTIFICATE" \ + -inkey "$MY_PRIVATE_KEY" \ + -noattr \ + -nodetach \ + -nosmimecap \ + -outform der \ + -out "$MY_POLICY.p7b" + +Deploying the policies is done through securityfs, through the +``new_policy`` node. To deploy a policy, simply cat the file into the +securityfs node:: + + cat "$MY_POLICY.p7b" > /sys/kernel/security/ipe/new_policy + +Upon success, this will create one subdirectory under +``/sys/kernel/security/ipe/policies/``. The subdirectory will be the +``policy_name`` field of the policy deployed, so for the example above, +the directory will be ``/sys/kernel/security/ipe/policies/Ex_Policy``. +Within this directory, there will be seven files: ``pkcs7``, ``policy``, +``name``, ``version``, ``active``, ``update``, and ``delete``. + +The ``pkcs7`` file is read-only. Reading it returns the raw PKCS#7 data +that was provided to the kernel, representing the policy. If the policy being +read is the boot policy, this will return ``ENOENT``, as it is not signed. + +The ``policy`` file is read only. Reading it returns the PKCS#7 inner +content of the policy, which will be the plain text policy. + +The ``active`` file is used to set a policy as the currently active policy. +This file is rw, and accepts a value of ``"1"`` to set the policy as active. +Since only a single policy can be active at one time, all other policies +will be marked inactive. The policy being marked active must have a policy +version greater or equal to the currently-running version. + +The ``update`` file is used to update a policy that is already present +in the kernel. This file is write-only and accepts a PKCS#7 signed +policy. Two checks will always be performed on this policy: First, the +``policy_names`` must match with the updated version and the existing +version. Second the updated policy must have a policy version greater than +or equal to the currently-running version. This is to prevent rollback attacks. + +The ``delete`` file is used to remove a policy that is no longer needed. +This file is write-only and accepts a value of ``1`` to delete the policy. +On deletion, the securityfs node representing the policy will be removed. +However, delete the current active policy is not allowed and will return +an operation not permitted error. + +Similarly, writing to both ``update`` and ``new_policy`` could result in +bad message(policy syntax error) or file exists error. The latter error happens +when trying to deploy a policy with a ``policy_name`` while the kernel already +has a deployed policy with the same ``policy_name``. + +Deploying a policy will *not* cause IPE to start enforcing the policy. IPE will +only enforce the policy marked active. Note that only one policy can be active +at a time. + +Once deployment is successful, the policy can be activated, by writing file +``/sys/kernel/security/ipe/policies/$policy_name/active``. +For example, the ``Ex_Policy`` can be activated by:: + + echo 1 > "/sys/kernel/security/ipe/policies/Ex_Policy/active" + +From above point on, ``Ex_Policy`` is now the enforced policy on the +system. + +IPE also provides a way to delete policies. This can be done via the +``delete`` securityfs node, +``/sys/kernel/security/ipe/policies/$policy_name/delete``. +Writing ``1`` to that file deletes the policy:: + + echo 1 > "/sys/kernel/security/ipe/policies/$policy_name/delete" + +There is only one requirement to delete a policy: the policy being deleted +must be inactive. + +.. NOTE:: + + If a traditional MAC system is enabled (SELinux, apparmor, smack), all + writes to ipe's securityfs nodes require ``CAP_MAC_ADMIN``. + +Modes +~~~~~ + +IPE supports two modes of operation: permissive (similar to SELinux's +permissive mode) and enforced. In permissive mode, all events are +checked and policy violations are logged, but the policy is not really +enforced. This allows users to test policies before enforcing them. + +The default mode is enforce, and can be changed via the kernel command +line parameter ``ipe.enforce=(0|1)``, or the securityfs node +``/sys/kernel/security/ipe/enforce``. + +.. NOTE:: + + If a traditional MAC system is enabled (SELinux, apparmor, smack, etcetera), + all writes to ipe's securityfs nodes require ``CAP_MAC_ADMIN``. + +Audit Events +~~~~~~~~~~~~ + +1420 AUDIT_IPE_ACCESS +^^^^^^^^^^^^^^^^^^^^^ +Event Examples:: + + type=1420 audit(1653364370.067:61): ipe_op=EXECUTE ipe_hook=MMAP enforcing=1 pid=2241 comm="ld-linux.so" path="/deny/lib/libc.so.6" dev="sda2" ino=14549020 rule="DEFAULT action=DENY" + type=1300 audit(1653364370.067:61): SYSCALL arch=c000003e syscall=9 success=no exit=-13 a0=7f1105a28000 a1=195000 a2=5 a3=812 items=0 ppid=2219 pid=2241 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=2 comm="ld-linux.so" exe="/tmp/ipe-test/lib/ld-linux.so" subj=unconfined key=(null) + type=1327 audit(1653364370.067:61): 707974686F6E3300746573742F6D61696E2E7079002D6E00 + + type=1420 audit(1653364735.161:64): ipe_op=EXECUTE ipe_hook=MMAP enforcing=1 pid=2472 comm="mmap_test" path=? dev=? ino=? rule="DEFAULT action=DENY" + type=1300 audit(1653364735.161:64): SYSCALL arch=c000003e syscall=9 success=no exit=-13 a0=0 a1=1000 a2=4 a3=21 items=0 ppid=2219 pid=2472 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=2 comm="mmap_test" exe="/root/overlake_test/upstream_test/vol_fsverity/bin/mmap_test" subj=unconfined key=(null) + type=1327 audit(1653364735.161:64): 707974686F6E3300746573742F6D61696E2E7079002D6E00 + +This event indicates that IPE made an access control decision; the IPE +specific record (1420) is always emitted in conjunction with a +``AUDITSYSCALL`` record. + +Determining whether IPE is in permissive or enforced mode can be derived +from ``success`` property and exit code of the ``AUDITSYSCALL`` record. + + +Field descriptions: + ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| Field | Value Type | Optional? | Description of Value | ++===========+============+===========+=================================================================================+ +| ipe_op | string | No | The IPE operation name associated with the log | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| ipe_hook | string | No | The name of the LSM hook that triggered the IPE event | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| enforcing | integer | No | The current IPE enforcing state 1 is in enforcing mode, 0 is in permissive mode | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| pid | integer | No | The pid of the process that triggered the IPE event. | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| comm | string | No | The command line program name of the process that triggered the IPE event | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| path | string | Yes | The absolute path to the evaluated file | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| ino | integer | Yes | The inode number of the evaluated file | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| dev | string | Yes | The device name of the evaluated file, e.g. vda | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ +| rule | string | No | The matched policy rule | ++-----------+------------+-----------+---------------------------------------------------------------------------------+ + +1421 AUDIT_IPE_CONFIG_CHANGE +^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Event Example:: + + type=1421 audit(1653425583.136:54): old_active_pol_name="Allow_All" old_active_pol_version=0.0.0 old_policy_digest=sha256:E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855 new_active_pol_name="boot_verified" new_active_pol_version=0.0.0 new_policy_digest=sha256:820EEA5B40CA42B51F68962354BA083122A20BB846F26765076DD8EED7B8F4DB auid=4294967295 ses=4294967295 lsm=ipe res=1 + type=1300 audit(1653425583.136:54): SYSCALL arch=c000003e syscall=1 success=yes exit=2 a0=3 a1=5596fcae1fb0 a2=2 a3=2 items=0 ppid=184 pid=229 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=4294967295 comm="python3" exe="/usr/bin/python3.10" key=(null) + type=1327 audit(1653425583.136:54): PROCTITLE proctitle=707974686F6E3300746573742F6D61696E2E7079002D66002E2 + +This event indicates that IPE switched the active poliy from one to another +along with the version and the hash digest of the two policies. +Note IPE can only have one policy active at a time, all access decision +evaluation is based on the current active policy. +The normal procedure to deploy a new policy is loading the policy to deploy +into the kernel first, then switch the active policy to it. + +This record will always be emitted in conjunction with a ``AUDITSYSCALL`` record for the ``write`` syscall. + +Field descriptions: + ++------------------------+------------+-----------+---------------------------------------------------+ +| Field | Value Type | Optional? | Description of Value | ++========================+============+===========+===================================================+ +| old_active_pol_name | string | Yes | The name of previous active policy | ++------------------------+------------+-----------+---------------------------------------------------+ +| old_active_pol_version | string | Yes | The version of previous active policy | ++------------------------+------------+-----------+---------------------------------------------------+ +| old_policy_digest | string | Yes | The hash of previous active policy | ++------------------------+------------+-----------+---------------------------------------------------+ +| new_active_pol_name | string | No | The name of current active policy | ++------------------------+------------+-----------+---------------------------------------------------+ +| new_active_pol_version | string | No | The version of current active policy | ++------------------------+------------+-----------+---------------------------------------------------+ +| new_policy_digest | string | No | The hash of current active policy | ++------------------------+------------+-----------+---------------------------------------------------+ +| auid | integer | No | The login user ID | ++------------------------+------------+-----------+---------------------------------------------------+ +| ses | integer | No | The login session ID | ++------------------------+------------+-----------+---------------------------------------------------+ +| lsm | string | No | The lsm name associated with the event | ++------------------------+------------+-----------+---------------------------------------------------+ +| res | integer | No | The result of the audited operation(success/fail) | ++------------------------+------------+-----------+---------------------------------------------------+ + +1422 AUDIT_IPE_POLICY_LOAD +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Event Example:: + + type=1422 audit(1653425529.927:53): policy_name="boot_verified" policy_version=0.0.0 policy_digest=sha256:820EEA5B40CA42B51F68962354BA083122A20BB846F26765076DD8EED7B8F4DB auid=4294967295 ses=4294967295 lsm=ipe res=1 + type=1300 audit(1653425529.927:53): arch=c000003e syscall=1 success=yes exit=2567 a0=3 a1=5596fcae1fb0 a2=a07 a3=2 items=0 ppid=184 pid=229 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=4294967295 comm="python3" exe="/usr/bin/python3.10" key=(null) + type=1327 audit(1653425529.927:53): PROCTITLE proctitle=707974686F6E3300746573742F6D61696E2E7079002D66002E2E + +This record indicates a new policy has been loaded into the kernel with the policy name, policy version and policy hash. + +This record will always be emitted in conjunction with a ``AUDITSYSCALL`` record for the ``write`` syscall. + +Field descriptions: + ++----------------+------------+-----------+---------------------------------------------------+ +| Field | Value Type | Optional? | Description of Value | ++================+============+===========+===================================================+ +| policy_name | string | No | The policy_name | ++----------------+------------+-----------+---------------------------------------------------+ +| policy_version | string | No | The policy_version | ++----------------+------------+-----------+---------------------------------------------------+ +| policy_digest | string | No | The policy hash | ++----------------+------------+-----------+---------------------------------------------------+ +| auid | integer | No | The login user ID | ++----------------+------------+-----------+---------------------------------------------------+ +| ses | integer | No | The login session ID | ++----------------+------------+-----------+---------------------------------------------------+ +| lsm | string | No | The lsm name associated with the event | ++----------------+------------+-----------+---------------------------------------------------+ +| res | integer | No | The result of the audited operation(success/fail) | ++----------------+------------+-----------+---------------------------------------------------+ + + +1404 AUDIT_MAC_STATUS +^^^^^^^^^^^^^^^^^^^^^ + +Event Examples:: + + type=1404 audit(1653425689.008:55): enforcing=0 old_enforcing=1 auid=4294967295 ses=4294967295 enabled=1 old-enabled=1 lsm=ipe res=1 + type=1300 audit(1653425689.008:55): arch=c000003e syscall=1 success=yes exit=2 a0=1 a1=55c1065e5c60 a2=2 a3=0 items=0 ppid=405 pid=441 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=) + type=1327 audit(1653425689.008:55): proctitle="-bash" + + type=1404 audit(1653425689.008:55): enforcing=1 old_enforcing=0 auid=4294967295 ses=4294967295 enabled=1 old-enabled=1 lsm=ipe res=1 + type=1300 audit(1653425689.008:55): arch=c000003e syscall=1 success=yes exit=2 a0=1 a1=55c1065e5c60 a2=2 a3=0 items=0 ppid=405 pid=441 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=) + type=1327 audit(1653425689.008:55): proctitle="-bash" + +This record will always be emitted in conjunction with a ``AUDITSYSCALL`` record for the ``write`` syscall. + +Field descriptions: + ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| Field | Value Type | Optional? | Description of Value | ++===============+============+===========+=================================================================================================+ +| enforcing | integer | No | The enforcing state IPE is being switched to, 1 is in enforcing mode, 0 is in permissive mode | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| old_enforcing | integer | No | The enforcing state IPE is being switched from, 1 is in enforcing mode, 0 is in permissive mode | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| auid | integer | No | The login user ID | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| ses | integer | No | The login session ID | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| enabled | integer | No | The new TTY audit enabled setting | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| old-enabled | integer | No | The old TTY audit enabled setting | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| lsm | string | No | The lsm name associated with the event | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ +| res | integer | No | The result of the audited operation(success/fail) | ++---------------+------------+-----------+-------------------------------------------------------------------------------------------------+ + + +Success Auditing +^^^^^^^^^^^^^^^^ + +IPE supports success auditing. When enabled, all events that pass IPE +policy and are not blocked will emit an audit event. This is disabled by +default, and can be enabled via the kernel command line +``ipe.success_audit=(0|1)`` or +``/sys/kernel/security/ipe/success_audit`` securityfs file. + +This is *very* noisy, as IPE will check every userspace binary on the +system, but is useful for debugging policies. + +.. NOTE:: + + If a traditional MAC system is enabled (SELinux, apparmor, smack, etcetera), + all writes to ipe's securityfs nodes require ``CAP_MAC_ADMIN``. + +Properties +---------- + +As explained above, IPE properties are ``key=value`` pairs expressed in IPE +policy. Two properties are built-into the policy parser: 'op' and 'action'. +The other properties are used to restrict immutable security properties +about the files being evaluated. Currently those properties are: +'``boot_verified``', '``dmverity_signature``', '``dmverity_roothash``', +'``fsverity_signature``', '``fsverity_digest``'. A description of all +properties supported by IPE are listed below: + +op +~~ + +Indicates the operation for a rule to apply to. Must be in every rule, +as the first token. IPE supports the following operations: + + ``EXECUTE`` + + Pertains to any file attempting to be executed, or loaded as an + executable. + + ``FIRMWARE``: + + Pertains to firmware being loaded via the firmware_class interface. + This covers both the preallocated buffer and the firmware file + itself. + + ``KMODULE``: + + Pertains to loading kernel modules via ``modprobe`` or ``insmod``. + + ``KEXEC_IMAGE``: + + Pertains to kernel images loading via ``kexec``. + + ``KEXEC_INITRAMFS`` + + Pertains to initrd images loading via ``kexec --initrd``. + + ``POLICY``: + + Controls loading policies via reading a kernel-space initiated read. + + An example of such is loading IMA policies by writing the path + to the policy file to ``$securityfs/ima/policy`` + + ``X509_CERT``: + + Controls loading IMA certificates through the Kconfigs, + ``CONFIG_IMA_X509_PATH`` and ``CONFIG_EVM_X509_PATH``. + +action +~~~~~~ + + Determines what IPE should do when a rule matches. Must be in every + rule, as the final clause. Can be one of: + + ``ALLOW``: + + If the rule matches, explicitly allow access to the resource to proceed + without executing any more rules. + + ``DENY``: + + If the rule matches, explicitly prohibit access to the resource to + proceed without executing any more rules. + +boot_verified +~~~~~~~~~~~~~ + + This property can be utilized for authorization of files from initramfs. + The format of this property is:: + + boot_verified=(TRUE|FALSE) + + + .. WARNING:: + + This property will trust files from initramfs(rootfs). It should + only be used during early booting stage. Before mounting the real + rootfs on top of the initramfs, initramfs script will recursively + remove all files and directories on the initramfs. This is typically + implemented by using switch_root(8) [#switch_root]_. Therefore the + initramfs will be empty and not accessible after the real + rootfs takes over. It is advised to switch to a different policy + that doesn't rely on the property after this point. + This ensures that the trust policies remain relevant and effective + throughout the system's operation. + +dmverity_roothash +~~~~~~~~~~~~~~~~~ + + This property can be utilized for authorization or revocation of + specific dm-verity volumes, identified via their root hashes. It has a + dependency on the DM_VERITY module. This property is controlled by + the ``IPE_PROP_DM_VERITY`` config option, it will be automatically + selected when ``SECURITY_IPE`` and ``DM_VERITY`` are all enabled. + The format of this property is:: + + dmverity_roothash=DigestName:HexadecimalString + + The supported DigestNames for dmverity_roothash are [#dmveritydigests]_ + + + blake2b-512 + + blake2s-256 + + sha256 + + sha384 + + sha512 + + sha3-224 + + sha3-256 + + sha3-384 + + sha3-512 + + sm3 + + rmd160 + +dmverity_signature +~~~~~~~~~~~~~~~~~~ + + This property can be utilized for authorization of all dm-verity + volumes that have a signed roothash that validated by a keyring + specified by dm-verity's configuration, either the system trusted + keyring, or the secondary keyring. It depends on + ``DM_VERITY_VERIFY_ROOTHASH_SIG`` config option and is controlled by + the ``IPE_PROP_DM_VERITY_SIGNATURE`` config option, it will be automatically + selected when ``SECURITY_IPE``, ``DM_VERITY`` and + ``DM_VERITY_VERIFY_ROOTHASH_SIG`` are all enabled. + The format of this property is:: + + dmverity_signature=(TRUE|FALSE) + +fsverity_digest +~~~~~~~~~~~~~~~ + + This property can be utilized for authorization of specific fsverity + enabled files, identified via their fsverity digests. + It depends on ``FS_VERITY`` config option and is controlled by + the ``IPE_PROP_FS_VERITY`` config option, it will be automatically + selected when ``SECURITY_IPE`` and ``FS_VERITY`` are all enabled. + The format of this property is:: + + fsverity_digest=DigestName:HexadecimalString + + The supported DigestNames for fsverity_digest are [#fsveritydigest]_ + + + sha256 + + sha512 + +fsverity_signature +~~~~~~~~~~~~~~~~~~ + + This property is used to authorize all fs-verity enabled files that have + been verified by fs-verity's built-in signature mechanism. The signature + verification relies on a key stored within the ".fs-verity" keyring. It + depends on ``FS_VERITY_BUILTIN_SIGNATURES`` config option and + it is controlled by the ``IPE_PROP_FS_VERITY`` config option, + it will be automatically selected when ``SECURITY_IPE``, ``FS_VERITY`` + and ``FS_VERITY_BUILTIN_SIGNATURES`` are all enabled. + The format of this property is:: + + fsverity_signature=(TRUE|FALSE) + +Policy Examples +--------------- + +Allow all +~~~~~~~~~ + +:: + + policy_name=Allow_All policy_version=0.0.0 + DEFAULT action=ALLOW + +Allow only initramfs +~~~~~~~~~~~~~~~~~~~~ + +:: + + policy_name=Allow_Initramfs policy_version=0.0.0 + DEFAULT action=DENY + + op=EXECUTE boot_verified=TRUE action=ALLOW + +Allow any signed and validated dm-verity volume and the initramfs +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +:: + + policy_name=Allow_Signed_DMV_And_Initramfs policy_version=0.0.0 + DEFAULT action=DENY + + op=EXECUTE boot_verified=TRUE action=ALLOW + op=EXECUTE dmverity_signature=TRUE action=ALLOW + +Prohibit execution from a specific dm-verity volume +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +:: + + policy_name=Deny_DMV_By_Roothash policy_version=0.0.0 + DEFAULT action=DENY + + op=EXECUTE dmverity_roothash=sha256:cd2c5bae7c6c579edaae4353049d58eb5f2e8be0244bf05345bc8e5ed257baff action=DENY + + op=EXECUTE boot_verified=TRUE action=ALLOW + op=EXECUTE dmverity_signature=TRUE action=ALLOW + +Allow only a specific dm-verity volume +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +:: + + policy_name=Allow_DMV_By_Roothash policy_version=0.0.0 + DEFAULT action=DENY + + op=EXECUTE dmverity_roothash=sha256:401fcec5944823ae12f62726e8184407a5fa9599783f030dec146938 action=ALLOW + +Allow any fs-verity file with a valid built-in signature +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +:: + + policy_name=Allow_Signed_And_Validated_FSVerity policy_version=0.0.0 + DEFAULT action=DENY + + op=EXECUTE fsverity_signature=TRUE action=ALLOW + +Allow execution of a specific fs-verity file +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +:: + + policy_name=ALLOW_FSV_By_Digest policy_version=0.0.0 + DEFAULT action=DENY + + op=EXECUTE fsverity_digest=sha256:fd88f2b8824e197f850bf4c5109bea5cf0ee38104f710843bb72da796ba5af9e action=ALLOW + +Additional Information +---------------------- + +- `Github Repository <https://github.com/microsoft/ipe>`_ +- :doc:`Developer and design docs for IPE </security/ipe>` + +FAQ +--- + +Q: + What's the difference between other LSMs which provide a measure of + trust-based access control? + +A: + + In general, there's two other LSMs that can provide similar functionality: + IMA, and Loadpin. + + IMA and IPE are functionally very similar. The significant difference between + the two is the policy. [#devdoc]_ + + Loadpin and IPE differ fairly dramatically, as Loadpin only covers the IPE's + kernel read operations, whereas IPE is capable of controlling execution + on top of kernel read. The trust model is also different; Loadpin roots its + trust in the initial super-block, whereas trust in IPE is stemmed from kernel + itself (via ``SYSTEM_TRUSTED_KEYS``). + +----------- + +.. [#digest_cache_lsm] https://lore.kernel.org/lkml/20240415142436.2545003-1-roberto.sassu@huaweicloud.com/ + +.. [#interpreters] There is `some interest in solving this issue <https://lore.kernel.org/lkml/20220321161557.495388-1-mic@digikod.net/>`_. + +.. [#devdoc] Please see :doc:`the design docs </security/ipe>` for more on + this topic. + +.. [#switch_root] https://man7.org/linux/man-pages/man8/switch_root.8.html + +.. [#dmveritydigests] These hash algorithms are based on values accepted by + the Linux crypto API; IPE does not impose any + restrictions on the digest algorithm itself; + thus, this list may be out of date. + +.. [#fsveritydigest] These hash algorithms are based on values accepted by the + kernel's fsverity support; IPE does not impose any + restrictions on the digest algorithm itself; + thus, this list may be out of date. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index be010fec7654..0b400aa28482 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2350,6 +2350,18 @@ ipcmni_extend [KNL,EARLY] Extend the maximum number of unique System V IPC identifiers from 32,768 to 16,777,216. + ipe.enforce= [IPE] + Format: <bool> + Determine whether IPE starts in permissive (0) or + enforce (1) mode. The default is enforce. + + ipe.success_audit= + [IPE] + Format: <bool> + Start IPE with success auditing enabled, emitting + an audit event when a binary is allowed. The default + is 0. + irqaffinity= [SMP] Set the default irq affinity mask The argument is a cpu list, as described above. diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst index 13e4b18e5dbb..0e2fac7a16da 100644 --- a/Documentation/filesystems/fsverity.rst +++ b/Documentation/filesystems/fsverity.rst @@ -86,6 +86,16 @@ authenticating fs-verity file hashes include: signature in their "security.ima" extended attribute, as controlled by the IMA policy. For more information, see the IMA documentation. +- Integrity Policy Enforcement (IPE). IPE supports enforcing access + control decisions based on immutable security properties of files, + including those protected by fs-verity's built-in signatures. + "IPE policy" specifically allows for the authorization of fs-verity + files using properties ``fsverity_digest`` for identifying + files by their verity digest, and ``fsverity_signature`` to authorize + files with a verified fs-verity's built-in signature. For + details on configuring IPE policies and understanding its operational + modes, please refer to :doc:`IPE admin guide </admin-guide/LSM/ipe>`. + - Trusted userspace code in combination with `Built-in signature verification`_. This approach should be used only with great care. @@ -457,7 +467,11 @@ Enabling this option adds the following: On success, the ioctl persists the signature alongside the Merkle tree. Then, any time the file is opened, the kernel verifies the file's actual digest against this signature, using the certificates - in the ".fs-verity" keyring. + in the ".fs-verity" keyring. This verification happens as long as the + file's signature exists, regardless of the state of the sysctl variable + "fs.verity.require_signatures" described in the next item. The IPE LSM + relies on this behavior to recognize and label fsverity files + that contain a verified built-in fsverity signature. 3. A new sysctl "fs.verity.require_signatures" is made available. When set to 1, the kernel requires that all verity files have a @@ -481,7 +495,7 @@ be carefully considered before using them: - Builtin signature verification does *not* make the kernel enforce that any files actually have fs-verity enabled. Thus, it is not a - complete authentication policy. Currently, if it is used, the only + complete authentication policy. Currently, if it is used, one way to complete the authentication policy is for trusted userspace code to explicitly check whether files have fs-verity enabled with a signature before they are accessed. (With @@ -490,6 +504,15 @@ be carefully considered before using them: could just store the signature alongside the file and verify it itself using a cryptographic library, instead of using this feature. +- Another approach is to utilize fs-verity builtin signature + verification in conjunction with the IPE LSM, which supports defining + a kernel-enforced, system-wide authentication policy that allows only + files with a verified fs-verity builtin signature to perform certain + operations, such as execution. Note that IPE doesn't require + fs.verity.require_signatures=1. + Please refer to :doc:`IPE admin guide </admin-guide/LSM/ipe>` for + more details. + - A file's builtin signature can only be set at the same time that fs-verity is being enabled on the file. Changing or deleting the builtin signature later requires re-creating the file. diff --git a/Documentation/security/index.rst b/Documentation/security/index.rst index 59f8fc106cb0..3e0a7114a862 100644 --- a/Documentation/security/index.rst +++ b/Documentation/security/index.rst @@ -19,3 +19,4 @@ Security Documentation digsig landlock secrets/index + ipe diff --git a/Documentation/security/ipe.rst b/Documentation/security/ipe.rst new file mode 100644 index 000000000000..4a7d953abcdc --- /dev/null +++ b/Documentation/security/ipe.rst @@ -0,0 +1,446 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Integrity Policy Enforcement (IPE) - Kernel Documentation +========================================================= + +.. NOTE:: + + This is documentation targeted at developers, instead of administrators. + If you're looking for documentation on the usage of IPE, please see + :doc:`IPE admin guide </admin-guide/LSM/ipe>`. + +Historical Motivation +--------------------- + +The original issue that prompted IPE's implementation was the creation +of a locked-down system. This system would be born-secure, and have +strong integrity guarantees over both the executable code, and specific +*data files* on the system, that were critical to its function. These +specific data files would not be readable unless they passed integrity +policy. A mandatory access control system would be present, and +as a result, xattrs would have to be protected. This lead to a selection +of what would provide the integrity claims. At the time, there were two +main mechanisms considered that could guarantee integrity for the system +with these requirements: + + 1. IMA + EVM Signatures + 2. DM-Verity + +Both options were carefully considered, however the choice to use DM-Verity +over IMA+EVM as the *integrity mechanism* in the original use case of IPE +was due to three main reasons: + + 1. Protection of additional attack vectors: + + * With IMA+EVM, without an encryption solution, the system is vulnerable + to offline attack against the aforementioned specific data files. + + Unlike executables, read operations (like those on the protected data + files), cannot be enforced to be globally integrity verified. This means + there must be some form of selector to determine whether a read should + enforce the integrity policy, or it should not. + + At the time, this was done with mandatory access control labels. An IMA + policy would indicate what labels required integrity verification, which + presented an issue: EVM would protect the label, but if an attacker could + modify filesystem offline, the attacker could wipe all the xattrs - + including the SELinux labels that would be used to determine whether the + file should be subject to integrity policy. + + With DM-Verity, as the xattrs are saved as part of the Merkel tree, if + offline mount occurs against the filesystem protected by dm-verity, the + checksum no longer matches and the file fails to be read. + + * As userspace binaries are paged in Linux, dm-verity also offers the + additional protection against a hostile block device. In such an attack, + the block device reports the appropriate content for the IMA hash + initially, passing the required integrity check. Then, on the page fault + that accesses the real data, will report the attacker's payload. Since + dm-verity will check the data when the page fault occurs (and the disk + access), this attack is mitigated. + + 2. Performance: + + * dm-verity provides integrity verification on demand as blocks are + read versus requiring the entire file being read into memory for + validation. + + 3. Simplicity of signing: + + * No need for two signatures (IMA, then EVM): one signature covers + an entire block device. + * Signatures can be stored externally to the filesystem metadata. + * The signature supports an x.509-based signing infrastructure. + +The next step was to choose a *policy* to enforce the integrity mechanism. +The minimum requirements for the policy were: + + 1. The policy itself must be integrity verified (preventing trivial + attack against it). + 2. The policy itself must be resistant to rollback attacks. + 3. The policy enforcement must have a permissive-like mode. + 4. The policy must be able to be updated, in its entirety, without + a reboot. + 5. Policy updates must be atomic. + 6. The policy must support *revocations* of previously authored + components. + 7. The policy must be auditable, at any point-of-time. + +IMA, as the only integrity policy mechanism at the time, was +considered against these list of requirements, and did not fulfill +all of the minimum requirements. Extending IMA to cover these +requirements was considered, but ultimately discarded for a +two reasons: + + 1. Regression risk; many of these changes would result in + dramatic code changes to IMA, which is already present in the + kernel, and therefore might impact users. + + 2. IMA was used in the system for measurement and attestation; + separation of measurement policy from local integrity policy + enforcement was considered favorable. + +Due to these reasons, it was decided that a new LSM should be created, +whose responsibility would be only the local integrity policy enforcement. + +Role and Scope +-------------- + +IPE, as its name implies, is fundamentally an integrity policy enforcement +solution; IPE does not mandate how integrity is provided, but instead +leaves that decision to the system administrator to set the security bar, +via the mechanisms that they select that suit their individual needs. +There are several different integrity solutions that provide a different +level of security guarantees; and IPE allows sysadmins to express policy for +theoretically all of them. + +IPE does not have an inherent mechanism to ensure integrity on its own. +Instead, there are more effective layers available for building systems that +can guarantee integrity. It's important to note that the mechanism for proving +integrity is independent of the policy for enforcing that integrity claim. + +Therefore, IPE was designed around: + + 1. Easy integrations with integrity providers. + 2. Ease of use for platform administrators/sysadmins. + +Design Rationale: +----------------- + +IPE was designed after evaluating existing integrity policy solutions +in other operating systems and environments. In this survey of other +implementations, there were a few pitfalls identified: + + 1. Policies were not readable by humans, usually requiring a binary + intermediary format. + 2. A single, non-customizable action was implicitly taken as a default. + 3. Debugging the policy required manual steps to determine what rule was violated. + 4. Authoring a policy required an in-depth knowledge of the larger system, + or operating system. + +IPE attempts to avoid all of these pitfalls. + +Policy +~~~~~~ + +Plain Text +^^^^^^^^^^ + +IPE's policy is plain-text. This introduces slightly larger policy files than +other LSMs, but solves two major problems that occurs with some integrity policy +solutions on other platforms. + +The first issue is one of code maintenance and duplication. To author policies, +the policy has to be some form of string representation (be it structured, +through XML, JSON, YAML, etcetera), to allow the policy author to understand +what is being written. In a hypothetical binary policy design, a serializer +is necessary to write the policy from the human readable form, to the binary +form, and a deserializer is needed to interpret the binary form into a data +structure in the kernel. + +Eventually, another deserializer will be needed to transform the binary from +back into the human-readable form with as much information preserved. This is because a +user of this access control system will have to keep a lookup table of a checksum +and the original file itself to try to understand what policies have been deployed +on this system and what policies have not. For a single user, this may be alright, +as old policies can be discarded almost immediately after the update takes hold. +For users that manage computer fleets in the thousands, if not hundreds of thousands, +with multiple different operating systems, and multiple different operational needs, +this quickly becomes an issue, as stale policies from years ago may be present, +quickly resulting in the need to recover the policy or fund extensive infrastructure +to track what each policy contains. + +With now three separate serializer/deserializers, maintenance becomes costly. If the +policy avoids the binary format, there is only one required serializer: from the +human-readable form to the data structure in kernel, saving on code maintenance, +and retaining operability. + +The second issue with a binary format is one of transparency. As IPE controls +access based on the trust of the system's resources, it's policy must also be +trusted to be changed. This is done through signatures, resulting in needing +signing as a process. Signing, as a process, is typically done with a +high security bar, as anything signed can be used to attack integrity +enforcement systems. It is also important that, when signing something, that +the signer is aware of what they are signing. A binary policy can cause +obfuscation of that fact; what signers see is an opaque binary blob. A +plain-text policy, on the other hand, the signers see the actual policy +submitted for signing. + +Boot Policy +~~~~~~~~~~~ + +IPE, if configured appropriately, is able to enforce a policy as soon as a +kernel is booted and usermode starts. That implies some level of storage +of the policy to apply the minute usermode starts. Generally, that storage +can be handled in one of three ways: + + 1. The policy file(s) live on disk and the kernel loads the policy prior + to an code path that would result in an enforcement decision. + 2. The policy file(s) are passed by the bootloader to the kernel, who + parses the policy. + 3. There is a policy file that is compiled into the kernel that is + parsed and enforced on initialization. + +The first option has problems: the kernel reading files from userspace +is typically discouraged and very uncommon in the kernel. + +The second option also has problems: Linux supports a variety of bootloaders +across its entire ecosystem - every bootloader would have to support this +new methodology or there must be an independent source. It would likely +result in more drastic changes to the kernel startup than necessary. + +The third option is the best but it's important to be aware that the policy +will take disk space against the kernel it's compiled in. It's important to +keep this policy generalized enough that userspace can load a new, more +complicated policy, but restrictive enough that it will not overauthorize +and cause security issues. + +The initramfs provides a way that this bootup path can be established. The +kernel starts with a minimal policy, that trusts the initramfs only. Inside +the initramfs, when the real rootfs is mounted, but not yet transferred to, +it deploys and activates a policy that trusts the new root filesystem. +This prevents overauthorization at any step, and keeps the kernel policy +to a minimal size. + +Startup +^^^^^^^ + +Not every system, however starts with an initramfs, so the startup policy +compiled into the kernel will need some flexibility to express how trust +is established for the next phase of the bootup. To this end, if we just +make the compiled-in policy a full IPE policy, it allows system builders +to express the first stage bootup requirements appropriately. + +Updatable, Rebootless Policy +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +As requirements change over time (vulnerabilities are found in previously +trusted applications, keys roll, etcetera). Updating a kernel to change the +meet those security goals is not always a suitable option, as updates are not +always risk-free, and blocking a security update leaves systems vulnerable. +This means IPE requires a policy that can be completely updated (allowing +revocations of existing policy) from a source external to the kernel (allowing +policies to be updated without updating the kernel). + +Additionally, since the kernel is stateless between invocations, and reading +policy files off the disk from kernel space is a bad idea(tm), then the +policy updates have to be done rebootlessly. + +To allow an update from an external source, it could be potentially malicious, +so this policy needs to have a way to be identified as trusted. This is +done via a signature chained to a trust source in the kernel. Arbitrarily, +this is the ``SYSTEM_TRUSTED_KEYRING``, a keyring that is initially +populated at kernel compile-time, as this matches the expectation that the +author of the compiled-in policy described above is the same entity that can +deploy policy updates. + +Anti-Rollback / Anti-Replay +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Over time, vulnerabilities are found and trusted resources may not be +trusted anymore. IPE's policy has no exception to this. There can be +instances where a mistaken policy author deploys an insecure policy, +before correcting it with a secure policy. + +Assuming that as soon as the insecure policy is signed, and an attacker +acquires the insecure policy, IPE needs a way to prevent rollback +from the secure policy update to the insecure policy update. + +Initially, IPE's policy can have a policy_version that states the +minimum required version across all policies that can be active on +the system. This will prevent rollback while the system is live. + +.. WARNING:: + + However, since the kernel is stateless across boots, this policy + version will be reset to 0.0.0 on the next boot. System builders + need to be aware of this, and ensure the new secure policies are + deployed ASAP after a boot to ensure that the window of + opportunity is minimal for an attacker to deploy the insecure policy. + +Implicit Actions: +~~~~~~~~~~~~~~~~~ + +The issue of implicit actions only becomes visible when you consider +a mixed level of security bars across multiple operations in a system. +For example, consider a system that has strong integrity guarantees +over both the executable code, and specific *data files* on the system, +that were critical to its function. In this system, three types of policies +are possible: + + 1. A policy in which failure to match any rules in the policy results + in the action being denied. + 2. A policy in which failure to match any rules in the policy results + in the action being allowed. + 3. A policy in which the action taken when no rules are matched is + specified by the policy author. + +The first option could make a policy like this:: + + op=EXECUTE integrity_verified=YES action=ALLOW + +In the example system, this works well for the executables, as all +executables should have integrity guarantees, without exception. The +issue becomes with the second requirement about specific data files. +This would result in a policy like this (assuming each line is +evaluated in order):: + + op=EXECUTE integrity_verified=YES action=ALLOW + + op=READ integrity_verified=NO label=critical_t action=DENY + op=READ action=ALLOW + +This is somewhat clear if you read the docs, understand the policy +is executed in order and that the default is a denial; however, the +last line effectively changes that default to an ALLOW. This is +required, because in a realistic system, there are some unverified +reads (imagine appending to a log file). + +The second option, matching no rules results in an allow, is clearer +for the specific data files:: + + op=READ integrity_verified=NO label=critical_t action=DENY + +And, like the first option, falls short with the execution scenario, +effectively needing to override the default:: + + op=EXECUTE integrity_verified=YES action=ALLOW + op=EXECUTE action=DENY + + op=READ integrity_verified=NO label=critical_t action=DENY + +This leaves the third option. Instead of making users be clever +and override the default with an empty rule, force the end-user +to consider what the appropriate default should be for their +scenario and explicitly state it:: + + DEFAULT op=EXECUTE action=DENY + op=EXECUTE integrity_verified=YES action=ALLOW + + DEFAULT op=READ action=ALLOW + op=READ integrity_verified=NO label=critical_t action=DENY + +Policy Debugging: +~~~~~~~~~~~~~~~~~ + +When developing a policy, it is useful to know what line of the policy +is being violated to reduce debugging costs; narrowing the scope of the +investigation to the exact line that resulted in the action. Some integrity +policy systems do not provide this information, instead providing the +information that was used in the evaluation. This then requires a correlation +with the policy to evaluate what went wrong. + +Instead, IPE just emits the rule that was matched. This limits the scope +of the investigation to the exact policy line (in the case of a specific +rule), or the section (in the case of a DEFAULT). This decreases iteration +and investigation times when policy failures are observed while evaluating +policies. + +IPE's policy engine is also designed in a way that it makes it obvious to +a human of how to investigate a policy failure. Each line is evaluated in +the sequence that is written, so the algorithm is very simple to follow +for humans to recreate the steps and could have caused the failure. In other +surveyed systems, optimizations occur (sorting rules, for instance) when loading +the policy. In those systems, it requires multiple steps to debug, and the +algorithm may not always be clear to the end-user without reading the code first. + +Simplified Policy: +~~~~~~~~~~~~~~~~~~ + +Finally, IPE's policy is designed for sysadmins, not kernel developers. Instead +of covering individual LSM hooks (or syscalls), IPE covers operations. This means +instead of sysadmins needing to know that the syscalls ``mmap``, ``mprotect``, +``execve``, and ``uselib`` must have rules protecting them, they must simple know +that they want to restrict code execution. This limits the amount of bypasses that +could occur due to a lack of knowledge of the underlying system; whereas the +maintainers of IPE, being kernel developers can make the correct choice to determine +whether something maps to these operations, and under what conditions. + +Implementation Notes +-------------------- + +Anonymous Memory +~~~~~~~~~~~~~~~~ + +Anonymous memory isn't treated any differently from any other access in IPE. +When anonymous memory is mapped with ``+X``, it still comes into the ``file_mmap`` +or ``file_mprotect`` hook, but with a ``NULL`` file object. This is submitted to +the evaluation, like any other file. However, all current trust properties will +evaluate to false, as they are all file-based and the operation is not +associated with a file. + +.. WARNING:: + + This also occurs with the ``kernel_load_data`` hook, when the kernel is + loading data from a userspace buffer that is not backed by a file. In this + scenario all current trust properties will also evaluate to false. + +Securityfs Interface +~~~~~~~~~~~~~~~~~~~~ + +The per-policy securityfs tree is somewhat unique. For example, for +a standard securityfs policy tree:: + + MyPolicy + |- active + |- delete + |- name + |- pkcs7 + |- policy + |- update + |- version + +The policy is stored in the ``->i_private`` data of the MyPolicy inode. + +Tests +----- + +IPE has KUnit Tests for the policy parser. Recommended kunitconfig:: + + CONFIG_KUNIT=y + CONFIG_SECURITY=y + CONFIG_SECURITYFS=y + CONFIG_PKCS7_MESSAGE_PARSER=y + CONFIG_SYSTEM_DATA_VERIFICATION=y + CONFIG_FS_VERITY=y + CONFIG_FS_VERITY_BUILTIN_SIGNATURES=y + CONFIG_BLOCK=y + CONFIG_MD=y + CONFIG_BLK_DEV_DM=y + CONFIG_DM_VERITY=y + CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG=y + CONFIG_NET=y + CONFIG_AUDIT=y + CONFIG_AUDITSYSCALL=y + CONFIG_BLK_DEV_INITRD=y + + CONFIG_SECURITY_IPE=y + CONFIG_IPE_PROP_DM_VERITY=y + CONFIG_IPE_PROP_DM_VERITY_SIGNATURE=y + CONFIG_IPE_PROP_FS_VERITY=y + CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG=y + CONFIG_SECURITY_IPE_KUNIT_TEST=y + +In addition, IPE has a python based integration +`test suite <https://github.com/microsoft/ipe/tree/test-suite>`_ that +can test both user interfaces and enforcement functionalities. diff --git a/MAINTAINERS b/MAINTAINERS index 7081f93bdb9a..5432239f3c5d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11166,6 +11166,16 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git F: security/integrity/ F: security/integrity/ima/ +INTEGRITY POLICY ENFORCEMENT (IPE) +M: Fan Wu <wufan@linux.microsoft.com> +L: linux-security-module@vger.kernel.org +S: Supported +T: git https://github.com/microsoft/ipe.git +F: Documentation/admin-guide/LSM/ipe.rst +F: Documentation/security/ipe.rst +F: scripts/ipe/ +F: security/ipe/ + INTEL 810/815 FRAMEBUFFER DRIVER M: Antonino Daplas <adaplas@gmail.com> L: linux-fbdev@vger.kernel.org diff --git a/block/bdev.c b/block/bdev.c index c5507b6f63b8..33f9c4605e3a 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -24,6 +24,7 @@ #include <linux/pseudo_fs.h> #include <linux/uio.h> #include <linux/namei.h> +#include <linux/security.h> #include <linux/part_stat.h> #include <linux/uaccess.h> #include <linux/stat.h> @@ -324,6 +325,11 @@ static struct inode *bdev_alloc_inode(struct super_block *sb) if (!ei) return NULL; memset(&ei->bdev, 0, sizeof(ei->bdev)); + + if (security_bdev_alloc(&ei->bdev)) { + kmem_cache_free(bdev_cachep, ei); + return NULL; + } return &ei->vfs_inode; } @@ -333,6 +339,7 @@ static void bdev_free_inode(struct inode *inode) free_percpu(bdev->bd_stats); kfree(bdev->bd_meta_info); + security_bdev_free(bdev); if (!bdev_is_partition(bdev)) { if (bdev->bd_disk && bdev->bd_disk->bdi) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index cf659c8feb29..24ba9a10444c 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -22,6 +22,7 @@ #include <linux/scatterlist.h> #include <linux/string.h> #include <linux/jump_label.h> +#include <linux/security.h> #define DM_MSG_PREFIX "verity" @@ -930,6 +931,41 @@ static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits) limits->dma_alignment = limits->logical_block_size - 1; } +#ifdef CONFIG_SECURITY + +static int verity_init_sig(struct dm_verity *v, const void *sig, + size_t sig_size) +{ + v->sig_size = sig_size; + + if (sig) { + v->root_digest_sig = kmemdup(sig, v->sig_size, GFP_KERNEL); + if (!v->root_digest_sig) + return -ENOMEM; + } + + return 0; +} + +static void verity_free_sig(struct dm_verity *v) +{ + kfree(v->root_digest_sig); +} + +#else + +static inline int verity_init_sig(struct dm_verity *v, const void *sig, + size_t sig_size) +{ + return 0; +} + +static inline void verity_free_sig(struct dm_verity *v) +{ +} + +#endif /* CONFIG_SECURITY */ + static void verity_dtr(struct dm_target *ti) { struct dm_verity *v = ti->private; @@ -949,6 +985,7 @@ static void verity_dtr(struct dm_target *ti) kfree(v->initial_hashstate); kfree(v->root_digest); kfree(v->zero_digest); + verity_free_sig(v); if (v->ahash_tfm) { static_branch_dec(&ahash_enabled); @@ -1418,6 +1455,13 @@ static int verity_ctr(struct dm_target *ti, unsigned int argc, char **argv) ti->error = "Root hash verification failed"; goto bad; } + + r = verity_init_sig(v, verify_args.sig, verify_args.sig_size); + if (r < 0) { + ti->error = "Cannot allocate root digest signature"; + goto bad; + } + v->hash_per_block_bits = __fls((1 << v->hash_dev_block_bits) / v->digest_size); @@ -1559,8 +1603,79 @@ int dm_verity_get_root_digest(struct dm_target *ti, u8 **root_digest, unsigned i return 0; } +#ifdef CONFIG_SECURITY + +#ifdef CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG + +static int verity_security_set_signature(struct block_device *bdev, + struct dm_verity *v) +{ + /* + * if the dm-verity target is unsigned, v->root_digest_sig will + * be NULL, and the hook call is still required to let LSMs mark + * the device as unsigned. This information is crucial for LSMs to + * block operations such as execution on unsigned files + */ + return security_bdev_setintegrity(bdev, + LSM_INT_DMVERITY_SIG_VALID, + v->root_digest_sig, + v->sig_size); +} + +#else + +static inline int verity_security_set_signature(struct block_device *bdev, + struct dm_verity *v) +{ + return 0; +} + +#endif /* CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG */ + +/* + * Expose verity target's root hash and signature data to LSMs before resume. + * + * Returns 0 on success, or -ENOMEM if the system is out of memory. + */ +static int verity_preresume(struct dm_target *ti) +{ + struct block_device *bdev; + struct dm_verity_digest root_digest; + struct dm_verity *v; + int r; + + v = ti->private; + bdev = dm_disk(dm_table_get_md(ti->table))->part0; + root_digest.digest = v->root_digest; + root_digest.digest_len = v->digest_size; + if (static_branch_unlikely(&ahash_enabled) && !v->shash_tfm) + root_digest.alg = crypto_ahash_alg_name(v->ahash_tfm); + else + root_digest.alg = crypto_shash_alg_name(v->shash_tfm); + + r = security_bdev_setintegrity(bdev, LSM_INT_DMVERITY_ROOTHASH, &root_digest, + sizeof(root_digest)); + if (r) + return r; + + r = verity_security_set_signature(bdev, v); + if (r) + goto bad; + + return 0; + +bad: + + security_bdev_setintegrity(bdev, LSM_INT_DMVERITY_ROOTHASH, NULL, 0); + + return r; +} + +#endif /* CONFIG_SECURITY */ + static struct target_type verity_target = { .name = "verity", +/* Note: the LSMs depend on the singleton and immutable features */ .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE, .version = {1, 10, 0}, .module = THIS_MODULE, @@ -1571,6 +1686,9 @@ static struct target_type verity_target = { .prepare_ioctl = verity_prepare_ioctl, .iterate_devices = verity_iterate_devices, .io_hints = verity_io_hints, +#ifdef CONFIG_SECURITY + .preresume = verity_preresume, +#endif /* CONFIG_SECURITY */ }; module_dm(verity); diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h index aac3a1b1d94a..754e70bb5fe0 100644 --- a/drivers/md/dm-verity.h +++ b/drivers/md/dm-verity.h @@ -45,6 +45,10 @@ struct dm_verity { u8 *salt; /* salt: its size is salt_size */ u8 *initial_hashstate; /* salted initial state, if shash_tfm is set */ u8 *zero_digest; /* digest for a zero block */ +#ifdef CONFIG_SECURITY + u8 *root_digest_sig; /* signature of the root digest */ + unsigned int sig_size; /* root digest signature size */ +#endif /* CONFIG_SECURITY */ unsigned int salt_size; sector_t data_start; /* data offset in 512-byte sectors */ sector_t hash_start; /* hash start in blocks */ diff --git a/fs/fcntl.c b/fs/fcntl.c index f6fde75a3bd5..081e5e3d89ea 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -125,8 +125,8 @@ void file_f_owner_release(struct file *file) } } -static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, - int force) +void __f_setown(struct file *filp, struct pid *pid, enum pid_type type, + int force) { struct fown_struct *f_owner; @@ -142,19 +142,13 @@ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, if (pid) { const struct cred *cred = current_cred(); + security_file_set_fowner(filp); f_owner->uid = cred->uid; f_owner->euid = cred->euid; } } write_unlock_irq(&f_owner->lock); } - -void __f_setown(struct file *filp, struct pid *pid, enum pid_type type, - int force) -{ - security_file_set_fowner(filp); - f_modown(filp, pid, type, force); -} EXPORT_SYMBOL(__f_setown); int f_setown(struct file *filp, int who, int force) @@ -196,7 +190,7 @@ EXPORT_SYMBOL(f_setown); void f_delown(struct file *filp) { - f_modown(filp, NULL, PIDTYPE_TGID, 1); + __f_setown(filp, NULL, PIDTYPE_TGID, 1); } pid_t f_getown(struct file *filp) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index a5ef2005a2cc..337a5be99ac9 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -115,12 +115,12 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de continue; error = security_inode_copy_up_xattr(old, name); - if (error < 0 && error != -EOPNOTSUPP) - break; - if (error == 1) { + if (error == -ECANCELED) { error = 0; continue; /* Discard */ } + if (error < 0 && error != -EOPNOTSUPP) + break; if (is_posix_acl_xattr(name)) { error = ovl_copy_acl(OVL_FS(sb), oldpath, new, name); diff --git a/fs/verity/signature.c b/fs/verity/signature.c index 90c07573dd77..0302a4e506ec 100644 --- a/fs/verity/signature.c +++ b/fs/verity/signature.c @@ -17,6 +17,7 @@ #include <linux/cred.h> #include <linux/key.h> +#include <linux/security.h> #include <linux/slab.h> #include <linux/verification.h> @@ -41,7 +42,11 @@ static struct key *fsverity_keyring; * @sig_size: size of signature in bytes, or 0 if no signature * * If the file includes a signature of its fs-verity file digest, verify it - * against the certificates in the fs-verity keyring. + * against the certificates in the fs-verity keyring. Note that signatures + * are verified regardless of the state of the 'fsverity_require_signatures' + * variable and the LSM subsystem relies on this behavior to help enforce + * file integrity policies. Please discuss changes with the LSM list + * (thank you!). * * Return: 0 on success (signature valid or not required); -errno on failure */ @@ -106,6 +111,17 @@ int fsverity_verify_signature(const struct fsverity_info *vi, return err; } + err = security_inode_setintegrity(inode, + LSM_INT_FSVERITY_BUILTINSIG_VALID, + signature, + sig_size); + + if (err) { + fsverity_err(inode, "Error %d exposing file signature to LSMs", + err); + return err; + } + return 0; } diff --git a/include/linux/args.h b/include/linux/args.h index 8ff60a54eb7d..2e8e65d975c7 100644 --- a/include/linux/args.h +++ b/include/linux/args.h @@ -17,9 +17,9 @@ * that as _n. */ -/* This counts to 12. Any more, it will return 13th argument. */ -#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n -#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) +/* This counts to 15. Any more, it will return 16th argument. */ +#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _n, X...) _n +#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) /* Concatenate two parameters, but allow them to be expanded beforehand. */ #define __CONCAT(a, b) a ## b diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 36ed96133217..413ebdff974b 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -71,6 +71,9 @@ struct block_device { struct partition_meta_info *bd_meta_info; int bd_writers; +#ifdef CONFIG_SECURITY + void *bd_security; +#endif /* * keep this out-of-line as it's both big and not needed in the fast * path diff --git a/include/linux/lsm_count.h b/include/linux/lsm_count.h new file mode 100644 index 000000000000..16eb49761b25 --- /dev/null +++ b/include/linux/lsm_count.h @@ -0,0 +1,135 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Copyright (C) 2023 Google LLC. + */ + +#ifndef __LINUX_LSM_COUNT_H +#define __LINUX_LSM_COUNT_H + +#include <linux/args.h> + +#ifdef CONFIG_SECURITY + +/* + * Macros to count the number of LSMs enabled in the kernel at compile time. + */ + +/* + * Capabilities is enabled when CONFIG_SECURITY is enabled. + */ +#if IS_ENABLED(CONFIG_SECURITY) +#define CAPABILITIES_ENABLED 1, +#else +#define CAPABILITIES_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_SELINUX) +#define SELINUX_ENABLED 1, +#else +#define SELINUX_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_SMACK) +#define SMACK_ENABLED 1, +#else +#define SMACK_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_APPARMOR) +#define APPARMOR_ENABLED 1, +#else +#define APPARMOR_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_TOMOYO) +#define TOMOYO_ENABLED 1, +#else +#define TOMOYO_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_YAMA) +#define YAMA_ENABLED 1, +#else +#define YAMA_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_LOADPIN) +#define LOADPIN_ENABLED 1, +#else +#define LOADPIN_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) +#define LOCKDOWN_ENABLED 1, +#else +#define LOCKDOWN_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_SAFESETID) +#define SAFESETID_ENABLED 1, +#else +#define SAFESETID_ENABLED +#endif + +#if IS_ENABLED(CONFIG_BPF_LSM) +#define BPF_LSM_ENABLED 1, +#else +#define BPF_LSM_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_LANDLOCK) +#define LANDLOCK_ENABLED 1, +#else +#define LANDLOCK_ENABLED +#endif + +#if IS_ENABLED(CONFIG_IMA) +#define IMA_ENABLED 1, +#else +#define IMA_ENABLED +#endif + +#if IS_ENABLED(CONFIG_EVM) +#define EVM_ENABLED 1, +#else +#define EVM_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_IPE) +#define IPE_ENABLED 1, +#else +#define IPE_ENABLED +#endif + +/* + * There is a trailing comma that we need to be accounted for. This is done by + * using a skipped argument in __COUNT_LSMS + */ +#define __COUNT_LSMS(skipped_arg, args...) COUNT_ARGS(args...) +#define COUNT_LSMS(args...) __COUNT_LSMS(args) + +#define MAX_LSM_COUNT \ + COUNT_LSMS( \ + CAPABILITIES_ENABLED \ + SELINUX_ENABLED \ + SMACK_ENABLED \ + APPARMOR_ENABLED \ + TOMOYO_ENABLED \ + YAMA_ENABLED \ + LOADPIN_ENABLED \ + LOCKDOWN_ENABLED \ + SAFESETID_ENABLED \ + BPF_LSM_ENABLED \ + LANDLOCK_ENABLED \ + IMA_ENABLED \ + EVM_ENABLED \ + IPE_ENABLED) + +#else + +#define MAX_LSM_COUNT 0 + +#endif /* CONFIG_SECURITY */ + +#endif /* __LINUX_LSM_COUNT_H */ diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 855db460e08b..1d59513bf230 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -48,7 +48,7 @@ LSM_HOOK(int, 0, quota_on, struct dentry *dentry) LSM_HOOK(int, 0, syslog, int type) LSM_HOOK(int, 0, settime, const struct timespec64 *ts, const struct timezone *tz) -LSM_HOOK(int, 1, vm_enough_memory, struct mm_struct *mm, long pages) +LSM_HOOK(int, 0, vm_enough_memory, struct mm_struct *mm, long pages) LSM_HOOK(int, 0, bprm_creds_for_exec, struct linux_binprm *bprm) LSM_HOOK(int, 0, bprm_creds_from_file, struct linux_binprm *bprm, const struct file *file) LSM_HOOK(int, 0, bprm_check_security, struct linux_binprm *bprm) @@ -114,6 +114,7 @@ LSM_HOOK(int, 0, path_notify, const struct path *path, u64 mask, unsigned int obj_type) LSM_HOOK(int, 0, inode_alloc_security, struct inode *inode) LSM_HOOK(void, LSM_RET_VOID, inode_free_security, struct inode *inode) +LSM_HOOK(void, LSM_RET_VOID, inode_free_security_rcu, void *inode_security) LSM_HOOK(int, -EOPNOTSUPP, inode_init_security, struct inode *inode, struct inode *dir, const struct qstr *qstr, struct xattr *xattrs, int *xattr_count) @@ -179,6 +180,8 @@ LSM_HOOK(void, LSM_RET_VOID, inode_getsecid, struct inode *inode, u32 *secid) LSM_HOOK(int, 0, inode_copy_up, struct dentry *src, struct cred **new) LSM_HOOK(int, -EOPNOTSUPP, inode_copy_up_xattr, struct dentry *src, const char *name) +LSM_HOOK(int, 0, inode_setintegrity, const struct inode *inode, + enum lsm_integrity_type type, const void *value, size_t size) LSM_HOOK(int, 0, kernfs_init_security, struct kernfs_node *kn_dir, struct kernfs_node *kn) LSM_HOOK(int, 0, file_permission, struct file *file, int mask) @@ -353,8 +356,7 @@ LSM_HOOK(void, LSM_RET_VOID, secmark_refcount_inc, void) LSM_HOOK(void, LSM_RET_VOID, secmark_refcount_dec, void) LSM_HOOK(void, LSM_RET_VOID, req_classify_flow, const struct request_sock *req, struct flowi_common *flic) -LSM_HOOK(int, 0, tun_dev_alloc_security, void **security) -LSM_HOOK(void, LSM_RET_VOID, tun_dev_free_security, void *security) +LSM_HOOK(int, 0, tun_dev_alloc_security, void *security) LSM_HOOK(int, 0, tun_dev_create, void) LSM_HOOK(int, 0, tun_dev_attach_queue, void *security) LSM_HOOK(int, 0, tun_dev_attach, struct sock *sk, void *security) @@ -374,8 +376,7 @@ LSM_HOOK(int, 0, mptcp_add_subflow, struct sock *sk, struct sock *ssk) LSM_HOOK(int, 0, ib_pkey_access, void *sec, u64 subnet_prefix, u16 pkey) LSM_HOOK(int, 0, ib_endport_manage_subnet, void *sec, const char *dev_name, u8 port_num) -LSM_HOOK(int, 0, ib_alloc_security, void **sec) -LSM_HOOK(void, LSM_RET_VOID, ib_free_security, void *sec) +LSM_HOOK(int, 0, ib_alloc_security, void *sec) #endif /* CONFIG_SECURITY_INFINIBAND */ #ifdef CONFIG_SECURITY_NETWORK_XFRM @@ -403,7 +404,6 @@ LSM_HOOK(int, 0, xfrm_decode_session, struct sk_buff *skb, u32 *secid, #ifdef CONFIG_KEYS LSM_HOOK(int, 0, key_alloc, struct key *key, const struct cred *cred, unsigned long flags) -LSM_HOOK(void, LSM_RET_VOID, key_free, struct key *key) LSM_HOOK(int, 0, key_permission, key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm) LSM_HOOK(int, 0, key_getsecurity, struct key *key, char **buffer) @@ -442,7 +442,6 @@ LSM_HOOK(int, 0, locked_down, enum lockdown_reason what) #ifdef CONFIG_PERF_EVENTS LSM_HOOK(int, 0, perf_event_open, struct perf_event_attr *attr, int type) LSM_HOOK(int, 0, perf_event_alloc, struct perf_event *event) -LSM_HOOK(void, LSM_RET_VOID, perf_event_free, struct perf_event *event) LSM_HOOK(int, 0, perf_event_read, struct perf_event *event) LSM_HOOK(int, 0, perf_event_write, struct perf_event *event) #endif /* CONFIG_PERF_EVENTS */ @@ -452,3 +451,10 @@ LSM_HOOK(int, 0, uring_override_creds, const struct cred *new) LSM_HOOK(int, 0, uring_sqpoll, void) LSM_HOOK(int, 0, uring_cmd, struct io_uring_cmd *ioucmd) #endif /* CONFIG_IO_URING */ + +LSM_HOOK(void, LSM_RET_VOID, initramfs_populated, void) + +LSM_HOOK(int, 0, bdev_alloc_security, struct block_device *bdev) +LSM_HOOK(void, LSM_RET_VOID, bdev_free_security, struct block_device *bdev) +LSM_HOOK(int, 0, bdev_setintegrity, struct block_device *bdev, + enum lsm_integrity_type type, const void *value, size_t size) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index a2ade0ffe9e7..090d1d3e19fe 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -30,19 +30,47 @@ #include <linux/init.h> #include <linux/rculist.h> #include <linux/xattr.h> +#include <linux/static_call.h> +#include <linux/unroll.h> +#include <linux/jump_label.h> +#include <linux/lsm_count.h> union security_list_options { #define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__); #include "lsm_hook_defs.h" #undef LSM_HOOK + void *lsm_func_addr; }; -struct security_hook_heads { - #define LSM_HOOK(RET, DEFAULT, NAME, ...) struct hlist_head NAME; - #include "lsm_hook_defs.h" - #undef LSM_HOOK +/* + * @key: static call key as defined by STATIC_CALL_KEY + * @trampoline: static call trampoline as defined by STATIC_CALL_TRAMP + * @hl: The security_hook_list as initialized by the owning LSM. + * @active: Enabled when the static call has an LSM hook associated. + */ +struct lsm_static_call { + struct static_call_key *key; + void *trampoline; + struct security_hook_list *hl; + /* this needs to be true or false based on what the key defaults to */ + struct static_key_false *active; } __randomize_layout; +/* + * Table of the static calls for each LSM hook. + * Once the LSMs are initialized, their callbacks will be copied to these + * tables such that the calls are filled backwards (from last to first). + * This way, we can jump directly to the first used static call, and execute + * all of them after. This essentially makes the entry point + * dynamic to adapt the number of static calls to the number of callbacks. + */ +struct lsm_static_calls_table { + #define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + struct lsm_static_call NAME[MAX_LSM_COUNT]; + #include <linux/lsm_hook_defs.h> + #undef LSM_HOOK +} __packed __randomize_layout; + /** * struct lsm_id - Identify a Linux Security Module. * @lsm: name of the LSM, must be approved by the LSM maintainers @@ -51,53 +79,45 @@ struct security_hook_heads { * Contains the information that identifies the LSM. */ struct lsm_id { - const char *name; - u64 id; + const char *name; + u64 id; }; /* * Security module hook list structure. * For use with generic list macros for common operations. + * + * struct security_hook_list - Contents of a cacheable, mappable object. + * @scalls: The beginning of the array of static calls assigned to this hook. + * @hook: The callback for the hook. + * @lsm: The name of the lsm that owns this hook. */ struct security_hook_list { - struct hlist_node list; - struct hlist_head *head; - union security_list_options hook; - const struct lsm_id *lsmid; + struct lsm_static_call *scalls; + union security_list_options hook; + const struct lsm_id *lsmid; } __randomize_layout; /* * Security blob size or offset data. */ struct lsm_blob_sizes { - int lbs_cred; - int lbs_file; - int lbs_inode; - int lbs_superblock; - int lbs_ipc; - int lbs_msg_msg; - int lbs_task; - int lbs_xattr_count; /* number of xattr slots in new_xattrs array */ + int lbs_cred; + int lbs_file; + int lbs_ib; + int lbs_inode; + int lbs_sock; + int lbs_superblock; + int lbs_ipc; + int lbs_key; + int lbs_msg_msg; + int lbs_perf_event; + int lbs_task; + int lbs_xattr_count; /* number of xattr slots in new_xattrs array */ + int lbs_tun_dev; + int lbs_bdev; }; -/** - * lsm_get_xattr_slot - Return the next available slot and increment the index - * @xattrs: array storing LSM-provided xattrs - * @xattr_count: number of already stored xattrs (updated) - * - * Retrieve the first available slot in the @xattrs array to fill with an xattr, - * and increment @xattr_count. - * - * Return: The slot to fill in @xattrs if non-NULL, NULL otherwise. - */ -static inline struct xattr *lsm_get_xattr_slot(struct xattr *xattrs, - int *xattr_count) -{ - if (unlikely(!xattrs)) - return NULL; - return &xattrs[(*xattr_count)++]; -} - /* * LSM_RET_VOID is used as the default value in LSM_HOOK definitions for void * LSM hooks (in include/linux/lsm_hook_defs.h). @@ -110,11 +130,11 @@ static inline struct xattr *lsm_get_xattr_slot(struct xattr *xattrs, * care of the common case and reduces the amount of * text involved. */ -#define LSM_HOOK_INIT(HEAD, HOOK) \ - { .head = &security_hook_heads.HEAD, .hook = { .HEAD = HOOK } } - -extern struct security_hook_heads security_hook_heads; -extern char *lsm_names; +#define LSM_HOOK_INIT(NAME, HOOK) \ + { \ + .scalls = static_calls_table.NAME, \ + .hook = { .NAME = HOOK } \ + } extern void security_add_hooks(struct security_hook_list *hooks, int count, const struct lsm_id *lsmid); @@ -137,9 +157,6 @@ struct lsm_info { struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */ }; -extern struct lsm_info __start_lsm_info[], __end_lsm_info[]; -extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[]; - #define DEFINE_LSM(lsm) \ static struct lsm_info __lsm_##lsm \ __used __section(".lsm_info.init") \ @@ -150,6 +167,28 @@ extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[]; __used __section(".early_lsm_info.init") \ __aligned(sizeof(unsigned long)) -extern int lsm_inode_alloc(struct inode *inode); +/* DO NOT tamper with these variables outside of the LSM framework */ +extern char *lsm_names; +extern struct lsm_static_calls_table static_calls_table __ro_after_init; +extern struct lsm_info __start_lsm_info[], __end_lsm_info[]; +extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[]; + +/** + * lsm_get_xattr_slot - Return the next available slot and increment the index + * @xattrs: array storing LSM-provided xattrs + * @xattr_count: number of already stored xattrs (updated) + * + * Retrieve the first available slot in the @xattrs array to fill with an xattr, + * and increment @xattr_count. + * + * Return: The slot to fill in @xattrs if non-NULL, NULL otherwise. + */ +static inline struct xattr *lsm_get_xattr_slot(struct xattr *xattrs, + int *xattr_count) +{ + if (unlikely(!xattrs)) + return NULL; + return &xattrs[(*xattr_count)++]; +} #endif /* ! __LINUX_LSM_HOOKS_H */ diff --git a/include/linux/security.h b/include/linux/security.h index 1390f1efb4f0..c37c32ebbdcd 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -83,6 +83,18 @@ enum lsm_event { LSM_POLICY_CHANGE, }; +struct dm_verity_digest { + const char *alg; + const u8 *digest; + size_t digest_len; +}; + +enum lsm_integrity_type { + LSM_INT_DMVERITY_SIG_VALID, + LSM_INT_DMVERITY_ROOTHASH, + LSM_INT_FSVERITY_BUILTINSIG_VALID, +}; + /* * These are reasons that can be passed to the security_locked_down() * LSM hook. Lockdown reasons that protect kernel integrity (ie, the @@ -399,6 +411,9 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer void security_inode_getsecid(struct inode *inode, u32 *secid); int security_inode_copy_up(struct dentry *src, struct cred **new); int security_inode_copy_up_xattr(struct dentry *src, const char *name); +int security_inode_setintegrity(const struct inode *inode, + enum lsm_integrity_type type, const void *value, + size_t size); int security_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn); int security_file_permission(struct file *file, int mask); @@ -509,6 +524,11 @@ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); int security_locked_down(enum lockdown_reason what); int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, u32 *uctx_len, void *val, size_t val_len, u64 id, u64 flags); +int security_bdev_alloc(struct block_device *bdev); +void security_bdev_free(struct block_device *bdev); +int security_bdev_setintegrity(struct block_device *bdev, + enum lsm_integrity_type type, const void *value, + size_t size); #else /* CONFIG_SECURITY */ static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data) @@ -634,7 +654,7 @@ static inline int security_settime64(const struct timespec64 *ts, static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) { - return __vm_enough_memory(mm, pages, cap_vm_enough_memory(mm, pages)); + return __vm_enough_memory(mm, pages, !cap_vm_enough_memory(mm, pages)); } static inline int security_bprm_creds_for_exec(struct linux_binprm *bprm) @@ -1010,6 +1030,13 @@ static inline int security_inode_copy_up(struct dentry *src, struct cred **new) return 0; } +static inline int security_inode_setintegrity(const struct inode *inode, + enum lsm_integrity_type type, + const void *value, size_t size) +{ + return 0; +} + static inline int security_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn) { @@ -1483,6 +1510,23 @@ static inline int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, { return -EOPNOTSUPP; } + +static inline int security_bdev_alloc(struct block_device *bdev) +{ + return 0; +} + +static inline void security_bdev_free(struct block_device *bdev) +{ +} + +static inline int security_bdev_setintegrity(struct block_device *bdev, + enum lsm_integrity_type type, + const void *value, size_t size) +{ + return 0; +} + #endif /* CONFIG_SECURITY */ #if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE) @@ -2090,6 +2134,7 @@ struct dentry *securityfs_create_symlink(const char *name, const char *target, const struct inode_operations *iops); extern void securityfs_remove(struct dentry *dentry); +extern void securityfs_recursive_remove(struct dentry *dentry); #else /* CONFIG_SECURITYFS */ @@ -2256,4 +2301,12 @@ static inline int security_uring_cmd(struct io_uring_cmd *ioucmd) #endif /* CONFIG_SECURITY */ #endif /* CONFIG_IO_URING */ +#ifdef CONFIG_SECURITY +extern void security_initramfs_populated(void); +#else +static inline void security_initramfs_populated(void) +{ +} +#endif /* CONFIG_SECURITY */ + #endif /* ! __LINUX_SECURITY_H */ diff --git a/include/linux/unroll.h b/include/linux/unroll.h new file mode 100644 index 000000000000..d42fd6366373 --- /dev/null +++ b/include/linux/unroll.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Copyright (C) 2023 Google LLC. + */ + +#ifndef __UNROLL_H +#define __UNROLL_H + +#include <linux/args.h> + +#define UNROLL(N, MACRO, args...) CONCATENATE(__UNROLL_, N)(MACRO, args) + +#define __UNROLL_0(MACRO, args...) +#define __UNROLL_1(MACRO, args...) __UNROLL_0(MACRO, args) MACRO(0, args) +#define __UNROLL_2(MACRO, args...) __UNROLL_1(MACRO, args) MACRO(1, args) +#define __UNROLL_3(MACRO, args...) __UNROLL_2(MACRO, args) MACRO(2, args) +#define __UNROLL_4(MACRO, args...) __UNROLL_3(MACRO, args) MACRO(3, args) +#define __UNROLL_5(MACRO, args...) __UNROLL_4(MACRO, args) MACRO(4, args) +#define __UNROLL_6(MACRO, args...) __UNROLL_5(MACRO, args) MACRO(5, args) +#define __UNROLL_7(MACRO, args...) __UNROLL_6(MACRO, args) MACRO(6, args) +#define __UNROLL_8(MACRO, args...) __UNROLL_7(MACRO, args) MACRO(7, args) +#define __UNROLL_9(MACRO, args...) __UNROLL_8(MACRO, args) MACRO(8, args) +#define __UNROLL_10(MACRO, args...) __UNROLL_9(MACRO, args) MACRO(9, args) +#define __UNROLL_11(MACRO, args...) __UNROLL_10(MACRO, args) MACRO(10, args) +#define __UNROLL_12(MACRO, args...) __UNROLL_11(MACRO, args) MACRO(11, args) +#define __UNROLL_13(MACRO, args...) __UNROLL_12(MACRO, args) MACRO(12, args) +#define __UNROLL_14(MACRO, args...) __UNROLL_13(MACRO, args) MACRO(13, args) +#define __UNROLL_15(MACRO, args...) __UNROLL_14(MACRO, args) MACRO(14, args) +#define __UNROLL_16(MACRO, args...) __UNROLL_15(MACRO, args) MACRO(15, args) +#define __UNROLL_17(MACRO, args...) __UNROLL_16(MACRO, args) MACRO(16, args) +#define __UNROLL_18(MACRO, args...) __UNROLL_17(MACRO, args) MACRO(17, args) +#define __UNROLL_19(MACRO, args...) __UNROLL_18(MACRO, args) MACRO(18, args) +#define __UNROLL_20(MACRO, args...) __UNROLL_19(MACRO, args) MACRO(19, args) + +#endif /* __UNROLL_H */ diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index d676ed2b246e..75e21a135483 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -143,6 +143,9 @@ #define AUDIT_MAC_UNLBL_STCDEL 1417 /* NetLabel: del a static label */ #define AUDIT_MAC_CALIPSO_ADD 1418 /* NetLabel: add CALIPSO DOI entry */ #define AUDIT_MAC_CALIPSO_DEL 1419 /* NetLabel: del CALIPSO DOI entry */ +#define AUDIT_IPE_ACCESS 1420 /* IPE denial or grant */ +#define AUDIT_IPE_CONFIG_CHANGE 1421 /* IPE config change */ +#define AUDIT_IPE_POLICY_LOAD 1422 /* IPE policy load */ #define AUDIT_FIRST_KERN_ANOM_MSG 1700 #define AUDIT_LAST_KERN_ANOM_MSG 1799 diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h index 33d8c9f4aa6b..938593dfd5da 100644 --- a/include/uapi/linux/lsm.h +++ b/include/uapi/linux/lsm.h @@ -64,6 +64,7 @@ struct lsm_ctx { #define LSM_ID_LANDLOCK 110 #define LSM_ID_IMA 111 #define LSM_ID_EVM 112 +#define LSM_ID_IPE 113 /* * LSM_ATTR_XXX definitions identify different LSM attributes diff --git a/init/initramfs.c b/init/initramfs.c index 814241b64827..bc911e466d5b 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -17,6 +17,7 @@ #include <linux/namei.h> #include <linux/init_syscalls.h> #include <linux/umh.h> +#include <linux/security.h> #include "do_mounts.h" @@ -712,6 +713,8 @@ static void __init do_populate_rootfs(void *unused, async_cookie_t cookie) } done: + security_initramfs_populated(); + /* * If the initrd region is overlapped with crashkernel reserved region, * free only memory that is not part of crashkernel region. diff --git a/init/main.c b/init/main.c index 206acdde51f5..c4778edae797 100644 --- a/init/main.c +++ b/init/main.c @@ -922,8 +922,11 @@ void start_kernel(void) boot_cpu_init(); page_address_init(); pr_notice("%s", linux_banner); - early_security_init(); setup_arch(&command_line); + /* Static keys and static calls are needed by LSMs */ + jump_label_init(); + static_call_init(); + early_security_init(); setup_boot_config(); setup_command_line(command_line); setup_nr_cpu_ids(); @@ -934,7 +937,6 @@ void start_kernel(void) pr_notice("Kernel command line: %s\n", saved_command_line); /* parameters may set static keys */ - jump_label_init(); parse_early_param(); after_dashes = parse_args("Booting kernel", static_command_line, __start___param, diff --git a/scripts/Makefile b/scripts/Makefile index dccef663ca82..6bcda4b9d054 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -55,6 +55,7 @@ targets += module.lds subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins subdir-$(CONFIG_MODVERSIONS) += genksyms subdir-$(CONFIG_SECURITY_SELINUX) += selinux +subdir-$(CONFIG_SECURITY_IPE) += ipe # Let clean descend into subdirs subdir- += basic dtc gdb kconfig mod diff --git a/scripts/ipe/Makefile b/scripts/ipe/Makefile new file mode 100644 index 000000000000..e87553fbb8d6 --- /dev/null +++ b/scripts/ipe/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +subdir-y := polgen diff --git a/scripts/ipe/polgen/.gitignore b/scripts/ipe/polgen/.gitignore new file mode 100644 index 000000000000..b6f05cf3dc0e --- /dev/null +++ b/scripts/ipe/polgen/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +polgen diff --git a/scripts/ipe/polgen/Makefile b/scripts/ipe/polgen/Makefile new file mode 100644 index 000000000000..c20456a2f2e9 --- /dev/null +++ b/scripts/ipe/polgen/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 +hostprogs-always-y := polgen +HOST_EXTRACFLAGS += \ + -I$(srctree)/include \ + -I$(srctree)/include/uapi \ diff --git a/scripts/ipe/polgen/polgen.c b/scripts/ipe/polgen/polgen.c new file mode 100644 index 000000000000..c6283b3ff006 --- /dev/null +++ b/scripts/ipe/polgen/polgen.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <stdlib.h> +#include <stddef.h> +#include <stdio.h> +#include <unistd.h> +#include <errno.h> + +static void usage(const char *const name) +{ + printf("Usage: %s OutputFile (PolicyFile)\n", name); + exit(EINVAL); +} + +static int policy_to_buffer(const char *pathname, char **buffer, size_t *size) +{ + size_t fsize; + size_t read; + char *lbuf; + int rc = 0; + FILE *fd; + + fd = fopen(pathname, "r"); + if (!fd) { + rc = errno; + goto out; + } + + fseek(fd, 0, SEEK_END); + fsize = ftell(fd); + rewind(fd); + + lbuf = malloc(fsize); + if (!lbuf) { + rc = ENOMEM; + goto out_close; + } + + read = fread((void *)lbuf, sizeof(*lbuf), fsize, fd); + if (read != fsize) { + rc = -1; + goto out_free; + } + + *buffer = lbuf; + *size = fsize; + fclose(fd); + + return rc; + +out_free: + free(lbuf); +out_close: + fclose(fd); +out: + return rc; +} + +static int write_boot_policy(const char *pathname, const char *buf, size_t size) +{ + int rc = 0; + FILE *fd; + size_t i; + + fd = fopen(pathname, "w"); + if (!fd) { + rc = errno; + goto err; + } + + fprintf(fd, "/* This file is automatically generated."); + fprintf(fd, " Do not edit. */\n"); + fprintf(fd, "#include <linux/stddef.h>\n"); + fprintf(fd, "\nextern const char *const ipe_boot_policy;\n\n"); + fprintf(fd, "const char *const ipe_boot_policy =\n"); + + if (!buf || size == 0) { + fprintf(fd, "\tNULL;\n"); + fclose(fd); + return 0; + } + + fprintf(fd, "\t\""); + + for (i = 0; i < size; ++i) { + switch (buf[i]) { + case '"': + fprintf(fd, "\\\""); + break; + case '\'': + fprintf(fd, "'"); + break; + case '\n': + fprintf(fd, "\\n\"\n\t\""); + break; + case '\\': + fprintf(fd, "\\\\"); + break; + case '\t': + fprintf(fd, "\\t"); + break; + case '\?': + fprintf(fd, "\\?"); + break; + default: + fprintf(fd, "%c", buf[i]); + } + } + fprintf(fd, "\";\n"); + fclose(fd); + + return 0; + +err: + if (fd) + fclose(fd); + return rc; +} + +int main(int argc, const char *const argv[]) +{ + char *policy = NULL; + size_t len = 0; + int rc = 0; + + if (argc < 2) + usage(argv[0]); + + if (argc > 2) { + rc = policy_to_buffer(argv[2], &policy, &len); + if (rc != 0) + goto cleanup; + } + + rc = write_boot_policy(argv[1], policy, len); +cleanup: + if (policy) + free(policy); + if (rc != 0) + perror("An error occurred during policy conversion: "); + return rc; +} diff --git a/security/Kconfig b/security/Kconfig index a93c1a9b7c28..28e685f53bd1 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -224,6 +224,7 @@ source "security/yama/Kconfig" source "security/safesetid/Kconfig" source "security/lockdown/Kconfig" source "security/landlock/Kconfig" +source "security/ipe/Kconfig" source "security/integrity/Kconfig" @@ -263,11 +264,11 @@ endchoice config LSM string "Ordered list of enabled LSMs" - default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK - default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR - default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO - default "landlock,lockdown,yama,loadpin,safesetid,bpf" if DEFAULT_SECURITY_DAC - default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf" + default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,ipe,bpf" if DEFAULT_SECURITY_SMACK + default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,ipe,bpf" if DEFAULT_SECURITY_APPARMOR + default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,ipe,bpf" if DEFAULT_SECURITY_TOMOYO + default "landlock,lockdown,yama,loadpin,safesetid,ipe,bpf" if DEFAULT_SECURITY_DAC + default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,ipe,bpf" help A comma-separated list of LSMs, in initialization order. Any LSMs left off this list, except for those with order diff --git a/security/Makefile b/security/Makefile index 59f238490665..cc0982214b84 100644 --- a/security/Makefile +++ b/security/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown/ obj-$(CONFIG_CGROUPS) += device_cgroup.o obj-$(CONFIG_BPF_LSM) += bpf/ obj-$(CONFIG_SECURITY_LANDLOCK) += landlock/ +obj-$(CONFIG_SECURITY_IPE) += ipe/ # Object integrity file lists obj-$(CONFIG_INTEGRITY) += integrity/ diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h index 67bf888c3bd6..c42ed8a73f1c 100644 --- a/security/apparmor/include/net.h +++ b/security/apparmor/include/net.h @@ -51,10 +51,9 @@ struct aa_sk_ctx { struct aa_label *peer; }; -#define SK_CTX(X) ((X)->sk_security) static inline struct aa_sk_ctx *aa_sock(const struct sock *sk) { - return sk->sk_security; + return sk->sk_security + apparmor_blob_sizes.lbs_sock; } #define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P) \ diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 808060f9effb..f5d05297d59e 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1058,27 +1058,12 @@ static int apparmor_userns_create(const struct cred *cred) return error; } -static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags) -{ - struct aa_sk_ctx *ctx; - - ctx = kzalloc(sizeof(*ctx), flags); - if (!ctx) - return -ENOMEM; - - sk->sk_security = ctx; - - return 0; -} - static void apparmor_sk_free_security(struct sock *sk) { struct aa_sk_ctx *ctx = aa_sock(sk); - sk->sk_security = NULL; aa_put_label(ctx->label); aa_put_label(ctx->peer); - kfree(ctx); } /** @@ -1433,6 +1418,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __ro_after_init = { .lbs_cred = sizeof(struct aa_label *), .lbs_file = sizeof(struct aa_file_ctx), .lbs_task = sizeof(struct aa_task_ctx), + .lbs_sock = sizeof(struct aa_sk_ctx), }; static const struct lsm_id apparmor_lsmid = { @@ -1478,7 +1464,6 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = { LSM_HOOK_INIT(getprocattr, apparmor_getprocattr), LSM_HOOK_INIT(setprocattr, apparmor_setprocattr), - LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security), LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security), LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security), diff --git a/security/apparmor/net.c b/security/apparmor/net.c index 87e934b2b548..77413a519117 100644 --- a/security/apparmor/net.c +++ b/security/apparmor/net.c @@ -151,7 +151,7 @@ static int aa_label_sk_perm(const struct cred *subj_cred, const char *op, u32 request, struct sock *sk) { - struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *ctx = aa_sock(sk); int error = 0; AA_BUG(!label); diff --git a/security/commoncap.c b/security/commoncap.c index 162d96b3a676..cefad323a0b1 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -1396,17 +1396,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, * Determine whether the allocation of a new virtual mapping by the current * task is permitted. * - * Return: 1 if permission is granted, 0 if not. + * Return: 0 if permission granted, negative error code if not. */ int cap_vm_enough_memory(struct mm_struct *mm, long pages) { - int cap_sys_admin = 0; - - if (cap_capable(current_cred(), &init_user_ns, - CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) == 0) - cap_sys_admin = 1; - - return cap_sys_admin; + return cap_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN, + CAP_OPT_NOAUDIT); } /** diff --git a/security/inode.c b/security/inode.c index 9e7cde913667..da3ab44c8e57 100644 --- a/security/inode.c +++ b/security/inode.c @@ -296,7 +296,7 @@ void securityfs_remove(struct dentry *dentry) { struct inode *dir; - if (!dentry || IS_ERR(dentry)) + if (IS_ERR_OR_NULL(dentry)) return; dir = d_inode(dentry->d_parent); @@ -313,6 +313,31 @@ void securityfs_remove(struct dentry *dentry) } EXPORT_SYMBOL_GPL(securityfs_remove); +static void remove_one(struct dentry *victim) +{ + simple_release_fs(&mount, &mount_count); +} + +/** + * securityfs_recursive_remove - recursively removes a file or directory + * + * @dentry: a pointer to a the dentry of the file or directory to be removed. + * + * This function recursively removes a file or directory in securityfs that was + * previously created with a call to another securityfs function (like + * securityfs_create_file() or variants thereof.) + */ +void securityfs_recursive_remove(struct dentry *dentry) +{ + if (IS_ERR_OR_NULL(dentry)) + return; + + simple_pin_fs(&fs_type, &mount, &mount_count); + simple_recursive_removal(dentry, remove_one); + simple_release_fs(&mount, &mount_count); +} +EXPORT_SYMBOL_GPL(securityfs_recursive_remove); + #ifdef CONFIG_SECURITY static struct dentry *lsm_dentry; static ssize_t lsm_read(struct file *filp, char __user *buf, size_t count, diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 62fe66dd53ce..6924ed508ebd 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -1000,7 +1000,7 @@ static int evm_inode_copy_up_xattr(struct dentry *src, const char *name) case EVM_XATTR_HMAC: case EVM_IMA_XATTR_DIGSIG: default: - rc = 1; /* discard */ + rc = -ECANCELED; /* discard */ } kfree(xattr_data); diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index c51e24d24d1e..3c323ca213d4 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -223,7 +223,7 @@ static inline void ima_inode_set_iint(const struct inode *inode, struct ima_iint_cache *ima_iint_find(struct inode *inode); struct ima_iint_cache *ima_inode_get(struct inode *inode); -void ima_inode_free(struct inode *inode); +void ima_inode_free_rcu(void *inode_security); void __init ima_iintcache_init(void); extern const int read_idmap[]; diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c index e23412a2c56b..00b249101f98 100644 --- a/security/integrity/ima/ima_iint.c +++ b/security/integrity/ima/ima_iint.c @@ -109,22 +109,18 @@ struct ima_iint_cache *ima_inode_get(struct inode *inode) } /** - * ima_inode_free - Called on inode free - * @inode: Pointer to the inode + * ima_inode_free_rcu - Called to free an inode via a RCU callback + * @inode_security: The inode->i_security pointer * - * Free the iint associated with an inode. + * Free the IMA data associated with an inode. */ -void ima_inode_free(struct inode *inode) +void ima_inode_free_rcu(void *inode_security) { - struct ima_iint_cache *iint; - - if (!IS_IMA(inode)) - return; - - iint = ima_iint_find(inode); - ima_inode_set_iint(inode, NULL); + struct ima_iint_cache **iint_p = inode_security + ima_blob_sizes.lbs_inode; - ima_iint_free(iint); + /* *iint_p should be NULL if !IS_IMA(inode) */ + if (*iint_p) + ima_iint_free(*iint_p); } static void ima_iint_init_once(void *foo) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index f04f43af651c..5b3394864b21 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -1193,7 +1193,7 @@ static struct security_hook_list ima_hooks[] __ro_after_init = { #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS LSM_HOOK_INIT(kernel_module_request, ima_kernel_module_request), #endif - LSM_HOOK_INIT(inode_free_security, ima_inode_free), + LSM_HOOK_INIT(inode_free_security_rcu, ima_inode_free_rcu), }; static const struct lsm_id ima_lsmid = { diff --git a/security/ipe/.gitignore b/security/ipe/.gitignore new file mode 100644 index 000000000000..6e9939be1cb7 --- /dev/null +++ b/security/ipe/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +boot_policy.c diff --git a/security/ipe/Kconfig b/security/ipe/Kconfig new file mode 100644 index 000000000000..3ab582606ed2 --- /dev/null +++ b/security/ipe/Kconfig @@ -0,0 +1,97 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Integrity Policy Enforcement (IPE) configuration +# + +menuconfig SECURITY_IPE + bool "Integrity Policy Enforcement (IPE)" + depends on SECURITY && SECURITYFS && AUDIT && AUDITSYSCALL + select PKCS7_MESSAGE_PARSER + select SYSTEM_DATA_VERIFICATION + select IPE_PROP_DM_VERITY if DM_VERITY + select IPE_PROP_DM_VERITY_SIGNATURE if DM_VERITY && DM_VERITY_VERIFY_ROOTHASH_SIG + select IPE_PROP_FS_VERITY if FS_VERITY + select IPE_PROP_FS_VERITY_BUILTIN_SIG if FS_VERITY && FS_VERITY_BUILTIN_SIGNATURES + help + This option enables the Integrity Policy Enforcement LSM + allowing users to define a policy to enforce a trust-based access + control. A key feature of IPE is a customizable policy to allow + admins to reconfigure trust requirements on the fly. + + If unsure, answer N. + +if SECURITY_IPE +config IPE_BOOT_POLICY + string "Integrity policy to apply on system startup" + help + This option specifies a filepath to an IPE policy that is compiled + into the kernel. This policy will be enforced until a policy update + is deployed via the $securityfs/ipe/policies/$policy_name/active + interface. + + If unsure, leave blank. + +menu "IPE Trust Providers" + +config IPE_PROP_DM_VERITY + bool "Enable support for dm-verity based on root hash" + depends on DM_VERITY + help + This option enables the 'dmverity_roothash' property within IPE + policies. The property evaluates to TRUE when a file from a dm-verity + volume is evaluated, and the volume's root hash matches the value + supplied in the policy. + +config IPE_PROP_DM_VERITY_SIGNATURE + bool "Enable support for dm-verity based on root hash signature" + depends on DM_VERITY && DM_VERITY_VERIFY_ROOTHASH_SIG + help + This option enables the 'dmverity_signature' property within IPE + policies. The property evaluates to TRUE when a file from a dm-verity + volume, which has been mounted with a valid signed root hash, + is evaluated. + + If unsure, answer Y. + +config IPE_PROP_FS_VERITY + bool "Enable support for fs-verity based on file digest" + depends on FS_VERITY + help + This option enables the 'fsverity_digest' property within IPE + policies. The property evaluates to TRUE when a file is fsverity + enabled and its digest matches the supplied digest value in the + policy. + + if unsure, answer Y. + +config IPE_PROP_FS_VERITY_BUILTIN_SIG + bool "Enable support for fs-verity based on builtin signature" + depends on FS_VERITY && FS_VERITY_BUILTIN_SIGNATURES + help + This option enables the 'fsverity_signature' property within IPE + policies. The property evaluates to TRUE when a file is fsverity + enabled and it has a valid builtin signature whose signing cert + is in the .fs-verity keyring. + + if unsure, answer Y. + +endmenu + +config SECURITY_IPE_KUNIT_TEST + bool "Build KUnit tests for IPE" if !KUNIT_ALL_TESTS + depends on KUNIT=y + default KUNIT_ALL_TESTS + help + This builds the IPE KUnit tests. + + KUnit tests run during boot and output the results to the debug log + in TAP format (https://testanything.org/). Only useful for kernel devs + running KUnit test harness and are not for inclusion into a + production build. + + For more information on KUnit and unit tests in general please refer + to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. + +endif diff --git a/security/ipe/Makefile b/security/ipe/Makefile new file mode 100644 index 000000000000..2ffabfa63fe9 --- /dev/null +++ b/security/ipe/Makefile @@ -0,0 +1,31 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. +# +# Makefile for building the IPE module as part of the kernel tree. +# + +quiet_cmd_polgen = IPE_POL $(2) + cmd_polgen = scripts/ipe/polgen/polgen security/ipe/boot_policy.c $(2) + +targets += boot_policy.c + +$(obj)/boot_policy.c: scripts/ipe/polgen/polgen $(CONFIG_IPE_BOOT_POLICY) FORCE + $(call if_changed,polgen,$(CONFIG_IPE_BOOT_POLICY)) + +obj-$(CONFIG_SECURITY_IPE) += \ + boot_policy.o \ + digest.o \ + eval.o \ + hooks.o \ + fs.o \ + ipe.o \ + policy.o \ + policy_fs.o \ + policy_parser.o \ + audit.o \ + +clean-files := boot_policy.c \ + +obj-$(CONFIG_SECURITY_IPE_KUNIT_TEST) += \ + policy_tests.o \ diff --git a/security/ipe/audit.c b/security/ipe/audit.c new file mode 100644 index 000000000000..f05f0caa4850 --- /dev/null +++ b/security/ipe/audit.c @@ -0,0 +1,292 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <linux/slab.h> +#include <linux/audit.h> +#include <linux/types.h> +#include <crypto/hash.h> + +#include "ipe.h" +#include "eval.h" +#include "hooks.h" +#include "policy.h" +#include "audit.h" +#include "digest.h" + +#define ACTSTR(x) ((x) == IPE_ACTION_ALLOW ? "ALLOW" : "DENY") + +#define IPE_AUDIT_HASH_ALG "sha256" + +#define AUDIT_POLICY_LOAD_FMT "policy_name=\"%s\" policy_version=%hu.%hu.%hu "\ + "policy_digest=" IPE_AUDIT_HASH_ALG ":" +#define AUDIT_OLD_ACTIVE_POLICY_FMT "old_active_pol_name=\"%s\" "\ + "old_active_pol_version=%hu.%hu.%hu "\ + "old_policy_digest=" IPE_AUDIT_HASH_ALG ":" +#define AUDIT_OLD_ACTIVE_POLICY_NULL_FMT "old_active_pol_name=? "\ + "old_active_pol_version=? "\ + "old_policy_digest=?" +#define AUDIT_NEW_ACTIVE_POLICY_FMT "new_active_pol_name=\"%s\" "\ + "new_active_pol_version=%hu.%hu.%hu "\ + "new_policy_digest=" IPE_AUDIT_HASH_ALG ":" + +static const char *const audit_op_names[__IPE_OP_MAX + 1] = { + "EXECUTE", + "FIRMWARE", + "KMODULE", + "KEXEC_IMAGE", + "KEXEC_INITRAMFS", + "POLICY", + "X509_CERT", + "UNKNOWN", +}; + +static const char *const audit_hook_names[__IPE_HOOK_MAX] = { + "BPRM_CHECK", + "MMAP", + "MPROTECT", + "KERNEL_READ", + "KERNEL_LOAD", +}; + +static const char *const audit_prop_names[__IPE_PROP_MAX] = { + "boot_verified=FALSE", + "boot_verified=TRUE", + "dmverity_roothash=", + "dmverity_signature=FALSE", + "dmverity_signature=TRUE", + "fsverity_digest=", + "fsverity_signature=FALSE", + "fsverity_signature=TRUE", +}; + +/** + * audit_dmv_roothash() - audit the roothash of a dmverity_roothash property. + * @ab: Supplies a pointer to the audit_buffer to append to. + * @rh: Supplies a pointer to the digest structure. + */ +static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) +{ + audit_log_format(ab, "%s", audit_prop_names[IPE_PROP_DMV_ROOTHASH]); + ipe_digest_audit(ab, rh); +} + +/** + * audit_fsv_digest() - audit the digest of a fsverity_digest property. + * @ab: Supplies a pointer to the audit_buffer to append to. + * @d: Supplies a pointer to the digest structure. + */ +static void audit_fsv_digest(struct audit_buffer *ab, const void *d) +{ + audit_log_format(ab, "%s", audit_prop_names[IPE_PROP_FSV_DIGEST]); + ipe_digest_audit(ab, d); +} + +/** + * audit_rule() - audit an IPE policy rule. + * @ab: Supplies a pointer to the audit_buffer to append to. + * @r: Supplies a pointer to the ipe_rule to approximate a string form for. + */ +static void audit_rule(struct audit_buffer *ab, const struct ipe_rule *r) +{ + const struct ipe_prop *ptr; + + audit_log_format(ab, " rule=\"op=%s ", audit_op_names[r->op]); + + list_for_each_entry(ptr, &r->props, next) { + switch (ptr->type) { + case IPE_PROP_DMV_ROOTHASH: + audit_dmv_roothash(ab, ptr->value); + break; + case IPE_PROP_FSV_DIGEST: + audit_fsv_digest(ab, ptr->value); + break; + default: + audit_log_format(ab, "%s", audit_prop_names[ptr->type]); + break; + } + + audit_log_format(ab, " "); + } + + audit_log_format(ab, "action=%s\"", ACTSTR(r->action)); +} + +/** + * ipe_audit_match() - Audit a rule match in a policy evaluation. + * @ctx: Supplies a pointer to the evaluation context that was used in the + * evaluation. + * @match_type: Supplies the scope of the match: rule, operation default, + * global default. + * @act: Supplies the IPE's evaluation decision, deny or allow. + * @r: Supplies a pointer to the rule that was matched, if possible. + */ +void ipe_audit_match(const struct ipe_eval_ctx *const ctx, + enum ipe_match match_type, + enum ipe_action_type act, const struct ipe_rule *const r) +{ + const char *op = audit_op_names[ctx->op]; + char comm[sizeof(current->comm)]; + struct audit_buffer *ab; + struct inode *inode; + + if (act != IPE_ACTION_DENY && !READ_ONCE(success_audit)) + return; + + ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN, + AUDIT_IPE_ACCESS); + if (!ab) + return; + + audit_log_format(ab, "ipe_op=%s ipe_hook=%s enforcing=%d pid=%d comm=", + op, audit_hook_names[ctx->hook], READ_ONCE(enforce), + task_tgid_nr(current)); + audit_log_untrustedstring(ab, get_task_comm(comm, current)); + + if (ctx->file) { + audit_log_d_path(ab, " path=", &ctx->file->f_path); + inode = file_inode(ctx->file); + if (inode) { + audit_log_format(ab, " dev="); + audit_log_untrustedstring(ab, inode->i_sb->s_id); + audit_log_format(ab, " ino=%lu", inode->i_ino); + } else { + audit_log_format(ab, " dev=? ino=?"); + } + } else { + audit_log_format(ab, " path=? dev=? ino=?"); + } + + if (match_type == IPE_MATCH_RULE) + audit_rule(ab, r); + else if (match_type == IPE_MATCH_TABLE) + audit_log_format(ab, " rule=\"DEFAULT op=%s action=%s\"", op, + ACTSTR(act)); + else + audit_log_format(ab, " rule=\"DEFAULT action=%s\"", + ACTSTR(act)); + + audit_log_end(ab); +} + +/** + * audit_policy() - Audit a policy's name, version and thumbprint to @ab. + * @ab: Supplies a pointer to the audit buffer to append to. + * @audit_format: Supplies a pointer to the audit format string + * @p: Supplies a pointer to the policy to audit. + */ +static void audit_policy(struct audit_buffer *ab, + const char *audit_format, + const struct ipe_policy *const p) +{ + SHASH_DESC_ON_STACK(desc, tfm); + struct crypto_shash *tfm; + u8 *digest = NULL; + + tfm = crypto_alloc_shash(IPE_AUDIT_HASH_ALG, 0, 0); + if (IS_ERR(tfm)) + return; + + desc->tfm = tfm; + + digest = kzalloc(crypto_shash_digestsize(tfm), GFP_KERNEL); + if (!digest) + goto out; + + if (crypto_shash_init(desc)) + goto out; + + if (crypto_shash_update(desc, p->pkcs7, p->pkcs7len)) + goto out; + + if (crypto_shash_final(desc, digest)) + goto out; + + audit_log_format(ab, audit_format, p->parsed->name, + p->parsed->version.major, p->parsed->version.minor, + p->parsed->version.rev); + audit_log_n_hex(ab, digest, crypto_shash_digestsize(tfm)); + +out: + kfree(digest); + crypto_free_shash(tfm); +} + +/** + * ipe_audit_policy_activation() - Audit a policy being activated. + * @op: Supplies a pointer to the previously activated policy to audit. + * @np: Supplies a pointer to the newly activated policy to audit. + */ +void ipe_audit_policy_activation(const struct ipe_policy *const op, + const struct ipe_policy *const np) +{ + struct audit_buffer *ab; + + ab = audit_log_start(audit_context(), GFP_KERNEL, + AUDIT_IPE_CONFIG_CHANGE); + if (!ab) + return; + + if (op) { + audit_policy(ab, AUDIT_OLD_ACTIVE_POLICY_FMT, op); + audit_log_format(ab, " "); + } else { + /* + * old active policy can be NULL if there is no kernel + * built-in policy + */ + audit_log_format(ab, AUDIT_OLD_ACTIVE_POLICY_NULL_FMT); + audit_log_format(ab, " "); + } + audit_policy(ab, AUDIT_NEW_ACTIVE_POLICY_FMT, np); + audit_log_format(ab, " auid=%u ses=%u lsm=ipe res=1", + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + + audit_log_end(ab); +} + +/** + * ipe_audit_policy_load() - Audit a policy being loaded into the kernel. + * @p: Supplies a pointer to the policy to audit. + */ +void ipe_audit_policy_load(const struct ipe_policy *const p) +{ + struct audit_buffer *ab; + + ab = audit_log_start(audit_context(), GFP_KERNEL, + AUDIT_IPE_POLICY_LOAD); + if (!ab) + return; + + audit_policy(ab, AUDIT_POLICY_LOAD_FMT, p); + audit_log_format(ab, " auid=%u ses=%u lsm=ipe res=1", + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + + audit_log_end(ab); +} + +/** + * ipe_audit_enforce() - Audit a change in IPE's enforcement state. + * @new_enforce: The new value enforce to be set. + * @old_enforce: The old value currently in enforce. + */ +void ipe_audit_enforce(bool new_enforce, bool old_enforce) +{ + struct audit_buffer *ab; + + ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS); + if (!ab) + return; + + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS, + "enforcing=%d old_enforcing=%d auid=%u ses=%u" + " enabled=1 old-enabled=1 lsm=ipe res=1", + new_enforce, old_enforce, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + + audit_log_end(ab); +} diff --git a/security/ipe/audit.h b/security/ipe/audit.h new file mode 100644 index 000000000000..ed2620846a79 --- /dev/null +++ b/security/ipe/audit.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#ifndef _IPE_AUDIT_H +#define _IPE_AUDIT_H + +#include "policy.h" + +void ipe_audit_match(const struct ipe_eval_ctx *const ctx, + enum ipe_match match_type, + enum ipe_action_type act, const struct ipe_rule *const r); +void ipe_audit_policy_load(const struct ipe_policy *const p); +void ipe_audit_policy_activation(const struct ipe_policy *const op, + const struct ipe_policy *const np); +void ipe_audit_enforce(bool new_enforce, bool old_enforce); + +#endif /* _IPE_AUDIT_H */ diff --git a/security/ipe/digest.c b/security/ipe/digest.c new file mode 100644 index 000000000000..493716370570 --- /dev/null +++ b/security/ipe/digest.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include "digest.h" + +/** + * ipe_digest_parse() - parse a digest in IPE's policy. + * @valstr: Supplies the string parsed from the policy. + * + * Digests in IPE are defined in a standard way: + * <alg_name>:<hex> + * + * Use this function to create a property to parse the digest + * consistently. The parsed digest will be saved in @value in IPE's + * policy. + * + * Return: The parsed digest_info structure on success. If an error occurs, + * the function will return the error value (via ERR_PTR). + */ +struct digest_info *ipe_digest_parse(const char *valstr) +{ + struct digest_info *info = NULL; + char *sep, *raw_digest; + size_t raw_digest_len; + u8 *digest = NULL; + char *alg = NULL; + int rc = 0; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return ERR_PTR(-ENOMEM); + + sep = strchr(valstr, ':'); + if (!sep) { + rc = -EBADMSG; + goto err; + } + + alg = kstrndup(valstr, sep - valstr, GFP_KERNEL); + if (!alg) { + rc = -ENOMEM; + goto err; + } + + raw_digest = sep + 1; + raw_digest_len = strlen(raw_digest); + + info->digest_len = (raw_digest_len + 1) / 2; + digest = kzalloc(info->digest_len, GFP_KERNEL); + if (!digest) { + rc = -ENOMEM; + goto err; + } + + rc = hex2bin(digest, raw_digest, info->digest_len); + if (rc < 0) { + rc = -EINVAL; + goto err; + } + + info->alg = alg; + info->digest = digest; + return info; + +err: + kfree(alg); + kfree(digest); + kfree(info); + return ERR_PTR(rc); +} + +/** + * ipe_digest_eval() - evaluate an IPE digest against another digest. + * @expected: Supplies the policy-provided digest value. + * @digest: Supplies the digest to compare against the policy digest value. + * + * Return: + * * %true - digests match + * * %false - digests do not match + */ +bool ipe_digest_eval(const struct digest_info *expected, + const struct digest_info *digest) +{ + return (expected->digest_len == digest->digest_len) && + (!strcmp(expected->alg, digest->alg)) && + (!memcmp(expected->digest, digest->digest, expected->digest_len)); +} + +/** + * ipe_digest_free() - free an IPE digest. + * @info: Supplies a pointer the policy-provided digest to free. + */ +void ipe_digest_free(struct digest_info *info) +{ + if (IS_ERR_OR_NULL(info)) + return; + + kfree(info->alg); + kfree(info->digest); + kfree(info); +} + +/** + * ipe_digest_audit() - audit a digest that was sourced from IPE's policy. + * @ab: Supplies the audit_buffer to append the formatted result. + * @info: Supplies a pointer to source the audit record from. + * + * Digests in IPE are audited in this format: + * <alg_name>:<hex> + */ +void ipe_digest_audit(struct audit_buffer *ab, const struct digest_info *info) +{ + audit_log_untrustedstring(ab, info->alg); + audit_log_format(ab, ":"); + audit_log_n_hex(ab, info->digest, info->digest_len); +} diff --git a/security/ipe/digest.h b/security/ipe/digest.h new file mode 100644 index 000000000000..52c9b3844a38 --- /dev/null +++ b/security/ipe/digest.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#ifndef _IPE_DIGEST_H +#define _IPE_DIGEST_H + +#include <linux/types.h> +#include <linux/audit.h> + +#include "policy.h" + +struct digest_info { + const char *alg; + const u8 *digest; + size_t digest_len; +}; + +struct digest_info *ipe_digest_parse(const char *valstr); +void ipe_digest_free(struct digest_info *digest_info); +void ipe_digest_audit(struct audit_buffer *ab, const struct digest_info *val); +bool ipe_digest_eval(const struct digest_info *expected, + const struct digest_info *digest); + +#endif /* _IPE_DIGEST_H */ diff --git a/security/ipe/eval.c b/security/ipe/eval.c new file mode 100644 index 000000000000..21439c5be336 --- /dev/null +++ b/security/ipe/eval.c @@ -0,0 +1,393 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <linux/fs.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/file.h> +#include <linux/sched.h> +#include <linux/rcupdate.h> +#include <linux/moduleparam.h> +#include <linux/fsverity.h> + +#include "ipe.h" +#include "eval.h" +#include "policy.h" +#include "audit.h" +#include "digest.h" + +struct ipe_policy __rcu *ipe_active_policy; +bool success_audit; +bool enforce = true; +#define INO_BLOCK_DEV(ino) ((ino)->i_sb->s_bdev) + +#define FILE_SUPERBLOCK(f) ((f)->f_path.mnt->mnt_sb) + +/** + * build_ipe_sb_ctx() - Build initramfs field of an ipe evaluation context. + * @ctx: Supplies a pointer to the context to be populated. + * @file: Supplies the file struct of the file triggered IPE event. + */ +static void build_ipe_sb_ctx(struct ipe_eval_ctx *ctx, const struct file *const file) +{ + ctx->initramfs = ipe_sb(FILE_SUPERBLOCK(file))->initramfs; +} + +#ifdef CONFIG_IPE_PROP_DM_VERITY +/** + * build_ipe_bdev_ctx() - Build ipe_bdev field of an evaluation context. + * @ctx: Supplies a pointer to the context to be populated. + * @ino: Supplies the inode struct of the file triggered IPE event. + */ +static void build_ipe_bdev_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino) +{ + if (INO_BLOCK_DEV(ino)) + ctx->ipe_bdev = ipe_bdev(INO_BLOCK_DEV(ino)); +} +#else +static void build_ipe_bdev_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino) +{ +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + +#ifdef CONFIG_IPE_PROP_FS_VERITY +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG +static void build_ipe_inode_blob_ctx(struct ipe_eval_ctx *ctx, + const struct inode *const ino) +{ + ctx->ipe_inode = ipe_inode(ctx->ino); +} +#else +static inline void build_ipe_inode_blob_ctx(struct ipe_eval_ctx *ctx, + const struct inode *const ino) +{ +} +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ + +/** + * build_ipe_inode_ctx() - Build inode fields of an evaluation context. + * @ctx: Supplies a pointer to the context to be populated. + * @ino: Supplies the inode struct of the file triggered IPE event. + */ +static void build_ipe_inode_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino) +{ + ctx->ino = ino; + build_ipe_inode_blob_ctx(ctx, ino); +} +#else +static void build_ipe_inode_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino) +{ +} +#endif /* CONFIG_IPE_PROP_FS_VERITY */ + +/** + * ipe_build_eval_ctx() - Build an ipe evaluation context. + * @ctx: Supplies a pointer to the context to be populated. + * @file: Supplies a pointer to the file to associated with the evaluation. + * @op: Supplies the IPE policy operation associated with the evaluation. + * @hook: Supplies the LSM hook associated with the evaluation. + */ +void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx, + const struct file *file, + enum ipe_op_type op, + enum ipe_hook_type hook) +{ + struct inode *ino; + + ctx->file = file; + ctx->op = op; + ctx->hook = hook; + + if (file) { + build_ipe_sb_ctx(ctx, file); + ino = d_real_inode(file->f_path.dentry); + build_ipe_bdev_ctx(ctx, ino); + build_ipe_inode_ctx(ctx, ino); + } +} + +/** + * evaluate_boot_verified() - Evaluate @ctx for the boot verified property. + * @ctx: Supplies a pointer to the context being evaluated. + * + * Return: + * * %true - The current @ctx match the @p + * * %false - The current @ctx doesn't match the @p + */ +static bool evaluate_boot_verified(const struct ipe_eval_ctx *const ctx) +{ + return ctx->initramfs; +} + +#ifdef CONFIG_IPE_PROP_DM_VERITY +/** + * evaluate_dmv_roothash() - Evaluate @ctx against a dmv roothash property. + * @ctx: Supplies a pointer to the context being evaluated. + * @p: Supplies a pointer to the property being evaluated. + * + * Return: + * * %true - The current @ctx match the @p + * * %false - The current @ctx doesn't match the @p + */ +static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return !!ctx->ipe_bdev && + !!ctx->ipe_bdev->root_hash && + ipe_digest_eval(p->value, + ctx->ipe_bdev->root_hash); +} +#else +static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return false; +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + +#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE +/** + * evaluate_dmv_sig_false() - Evaluate @ctx against a dmv sig false property. + * @ctx: Supplies a pointer to the context being evaluated. + * + * Return: + * * %true - The current @ctx match the property + * * %false - The current @ctx doesn't match the property + */ +static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx) +{ + return !ctx->ipe_bdev || (!ctx->ipe_bdev->dm_verity_signed); +} + +/** + * evaluate_dmv_sig_true() - Evaluate @ctx against a dmv sig true property. + * @ctx: Supplies a pointer to the context being evaluated. + * + * Return: + * * %true - The current @ctx match the property + * * %false - The current @ctx doesn't match the property + */ +static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx) +{ + return !evaluate_dmv_sig_false(ctx); +} +#else +static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx) +{ + return false; +} + +static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx) +{ + return false; +} +#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */ + +#ifdef CONFIG_IPE_PROP_FS_VERITY +/** + * evaluate_fsv_digest() - Evaluate @ctx against a fsv digest property. + * @ctx: Supplies a pointer to the context being evaluated. + * @p: Supplies a pointer to the property being evaluated. + * + * Return: + * * %true - The current @ctx match the @p + * * %false - The current @ctx doesn't match the @p + */ +static bool evaluate_fsv_digest(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + enum hash_algo alg; + u8 digest[FS_VERITY_MAX_DIGEST_SIZE]; + struct digest_info info; + + if (!ctx->ino) + return false; + if (!fsverity_get_digest((struct inode *)ctx->ino, + digest, + NULL, + &alg)) + return false; + + info.alg = hash_algo_name[alg]; + info.digest = digest; + info.digest_len = hash_digest_size[alg]; + + return ipe_digest_eval(p->value, &info); +} +#else +static bool evaluate_fsv_digest(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return false; +} +#endif /* CONFIG_IPE_PROP_FS_VERITY */ + +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG +/** + * evaluate_fsv_sig_false() - Evaluate @ctx against a fsv sig false property. + * @ctx: Supplies a pointer to the context being evaluated. + * + * Return: + * * %true - The current @ctx match the property + * * %false - The current @ctx doesn't match the property + */ +static bool evaluate_fsv_sig_false(const struct ipe_eval_ctx *const ctx) +{ + return !ctx->ino || + !IS_VERITY(ctx->ino) || + !ctx->ipe_inode || + !ctx->ipe_inode->fs_verity_signed; +} + +/** + * evaluate_fsv_sig_true() - Evaluate @ctx against a fsv sig true property. + * @ctx: Supplies a pointer to the context being evaluated. + * + * Return: + * * %true - The current @ctx match the property + * * %false - The current @ctx doesn't match the property + */ +static bool evaluate_fsv_sig_true(const struct ipe_eval_ctx *const ctx) +{ + return !evaluate_fsv_sig_false(ctx); +} +#else +static bool evaluate_fsv_sig_false(const struct ipe_eval_ctx *const ctx) +{ + return false; +} + +static bool evaluate_fsv_sig_true(const struct ipe_eval_ctx *const ctx) +{ + return false; +} +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ + +/** + * evaluate_property() - Analyze @ctx against a rule property. + * @ctx: Supplies a pointer to the context to be evaluated. + * @p: Supplies a pointer to the property to be evaluated. + * + * This function Determines whether the specified @ctx + * matches the conditions defined by a rule property @p. + * + * Return: + * * %true - The current @ctx match the @p + * * %false - The current @ctx doesn't match the @p + */ +static bool evaluate_property(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + switch (p->type) { + case IPE_PROP_BOOT_VERIFIED_FALSE: + return !evaluate_boot_verified(ctx); + case IPE_PROP_BOOT_VERIFIED_TRUE: + return evaluate_boot_verified(ctx); + case IPE_PROP_DMV_ROOTHASH: + return evaluate_dmv_roothash(ctx, p); + case IPE_PROP_DMV_SIG_FALSE: + return evaluate_dmv_sig_false(ctx); + case IPE_PROP_DMV_SIG_TRUE: + return evaluate_dmv_sig_true(ctx); + case IPE_PROP_FSV_DIGEST: + return evaluate_fsv_digest(ctx, p); + case IPE_PROP_FSV_SIG_FALSE: + return evaluate_fsv_sig_false(ctx); + case IPE_PROP_FSV_SIG_TRUE: + return evaluate_fsv_sig_true(ctx); + default: + return false; + } +} + +/** + * ipe_evaluate_event() - Analyze @ctx against the current active policy. + * @ctx: Supplies a pointer to the context to be evaluated. + * + * This is the loop where all policy evaluations happen against the IPE policy. + * + * Return: + * * %0 - Success + * * %-EACCES - @ctx did not pass evaluation + */ +int ipe_evaluate_event(const struct ipe_eval_ctx *const ctx) +{ + const struct ipe_op_table *rules = NULL; + const struct ipe_rule *rule = NULL; + struct ipe_policy *pol = NULL; + struct ipe_prop *prop = NULL; + enum ipe_action_type action; + enum ipe_match match_type; + bool match = false; + int rc = 0; + + rcu_read_lock(); + + pol = rcu_dereference(ipe_active_policy); + if (!pol) { + rcu_read_unlock(); + return 0; + } + + if (ctx->op == IPE_OP_INVALID) { + if (pol->parsed->global_default_action == IPE_ACTION_INVALID) { + WARN(1, "no default rule set for unknown op, ALLOW it"); + action = IPE_ACTION_ALLOW; + } else { + action = pol->parsed->global_default_action; + } + match_type = IPE_MATCH_GLOBAL; + goto eval; + } + + rules = &pol->parsed->rules[ctx->op]; + + list_for_each_entry(rule, &rules->rules, next) { + match = true; + + list_for_each_entry(prop, &rule->props, next) { + match = evaluate_property(ctx, prop); + if (!match) + break; + } + + if (match) + break; + } + + if (match) { + action = rule->action; + match_type = IPE_MATCH_RULE; + } else if (rules->default_action != IPE_ACTION_INVALID) { + action = rules->default_action; + match_type = IPE_MATCH_TABLE; + } else { + action = pol->parsed->global_default_action; + match_type = IPE_MATCH_GLOBAL; + } + +eval: + ipe_audit_match(ctx, match_type, action, rule); + rcu_read_unlock(); + + if (action == IPE_ACTION_DENY) + rc = -EACCES; + + if (!READ_ONCE(enforce)) + rc = 0; + + return rc; +} + +/* Set the right module name */ +#ifdef KBUILD_MODNAME +#undef KBUILD_MODNAME +#define KBUILD_MODNAME "ipe" +#endif + +module_param(success_audit, bool, 0400); +MODULE_PARM_DESC(success_audit, "Start IPE with success auditing enabled"); +module_param(enforce, bool, 0400); +MODULE_PARM_DESC(enforce, "Start IPE in enforce or permissive mode"); diff --git a/security/ipe/eval.h b/security/ipe/eval.h new file mode 100644 index 000000000000..fef65a36468c --- /dev/null +++ b/security/ipe/eval.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#ifndef _IPE_EVAL_H +#define _IPE_EVAL_H + +#include <linux/file.h> +#include <linux/types.h> + +#include "policy.h" +#include "hooks.h" + +#define IPE_EVAL_CTX_INIT ((struct ipe_eval_ctx){ 0 }) + +extern struct ipe_policy __rcu *ipe_active_policy; +extern bool success_audit; +extern bool enforce; + +struct ipe_superblock { + bool initramfs; +}; + +#ifdef CONFIG_IPE_PROP_DM_VERITY +struct ipe_bdev { +#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE + bool dm_verity_signed; +#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */ + struct digest_info *root_hash; +}; +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG +struct ipe_inode { + bool fs_verity_signed; +}; +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ + +struct ipe_eval_ctx { + enum ipe_op_type op; + enum ipe_hook_type hook; + + const struct file *file; + bool initramfs; +#ifdef CONFIG_IPE_PROP_DM_VERITY + const struct ipe_bdev *ipe_bdev; +#endif /* CONFIG_IPE_PROP_DM_VERITY */ +#ifdef CONFIG_IPE_PROP_FS_VERITY + const struct inode *ino; +#endif /* CONFIG_IPE_PROP_FS_VERITY */ +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG + const struct ipe_inode *ipe_inode; +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ +}; + +enum ipe_match { + IPE_MATCH_RULE = 0, + IPE_MATCH_TABLE, + IPE_MATCH_GLOBAL, + __IPE_MATCH_MAX +}; + +void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx, + const struct file *file, + enum ipe_op_type op, + enum ipe_hook_type hook); +int ipe_evaluate_event(const struct ipe_eval_ctx *const ctx); + +#endif /* _IPE_EVAL_H */ diff --git a/security/ipe/fs.c b/security/ipe/fs.c new file mode 100644 index 000000000000..5b6d19fb844a --- /dev/null +++ b/security/ipe/fs.c @@ -0,0 +1,247 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <linux/dcache.h> +#include <linux/security.h> + +#include "ipe.h" +#include "fs.h" +#include "eval.h" +#include "policy.h" +#include "audit.h" + +static struct dentry *np __ro_after_init; +static struct dentry *root __ro_after_init; +struct dentry *policy_root __ro_after_init; +static struct dentry *audit_node __ro_after_init; +static struct dentry *enforce_node __ro_after_init; + +/** + * setaudit() - Write handler for the securityfs node, "ipe/success_audit" + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * Return: + * * Length of buffer written - Success + * * %-EPERM - Insufficient permission + */ +static ssize_t setaudit(struct file *f, const char __user *data, + size_t len, loff_t *offset) +{ + int rc = 0; + bool value; + + if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + rc = kstrtobool_from_user(data, len, &value); + if (rc) + return rc; + + WRITE_ONCE(success_audit, value); + + return len; +} + +/** + * getaudit() - Read handler for the securityfs node, "ipe/success_audit" + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the read syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * Return: Length of buffer written + */ +static ssize_t getaudit(struct file *f, char __user *data, + size_t len, loff_t *offset) +{ + const char *result; + + result = ((READ_ONCE(success_audit)) ? "1" : "0"); + + return simple_read_from_buffer(data, len, offset, result, 1); +} + +/** + * setenforce() - Write handler for the securityfs node, "ipe/enforce" + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * Return: + * * Length of buffer written - Success + * * %-EPERM - Insufficient permission + */ +static ssize_t setenforce(struct file *f, const char __user *data, + size_t len, loff_t *offset) +{ + int rc = 0; + bool new_value, old_value; + + if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + old_value = READ_ONCE(enforce); + rc = kstrtobool_from_user(data, len, &new_value); + if (rc) + return rc; + + if (new_value != old_value) { + ipe_audit_enforce(new_value, old_value); + WRITE_ONCE(enforce, new_value); + } + + return len; +} + +/** + * getenforce() - Read handler for the securityfs node, "ipe/enforce" + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the read syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * Return: Length of buffer written + */ +static ssize_t getenforce(struct file *f, char __user *data, + size_t len, loff_t *offset) +{ + const char *result; + + result = ((READ_ONCE(enforce)) ? "1" : "0"); + + return simple_read_from_buffer(data, len, offset, result, 1); +} + +/** + * new_policy() - Write handler for the securityfs node, "ipe/new_policy". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * Return: + * * Length of buffer written - Success + * * %-EPERM - Insufficient permission + * * %-ENOMEM - Out of memory (OOM) + * * %-EBADMSG - Policy is invalid + * * %-ERANGE - Policy version number overflow + * * %-EINVAL - Policy version parsing error + * * %-EEXIST - Same name policy already deployed + */ +static ssize_t new_policy(struct file *f, const char __user *data, + size_t len, loff_t *offset) +{ + struct ipe_policy *p = NULL; + char *copy = NULL; + int rc = 0; + + if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + copy = memdup_user_nul(data, len); + if (IS_ERR(copy)) + return PTR_ERR(copy); + + p = ipe_new_policy(NULL, 0, copy, len); + if (IS_ERR(p)) { + rc = PTR_ERR(p); + goto out; + } + + rc = ipe_new_policyfs_node(p); + if (rc) + goto out; + + ipe_audit_policy_load(p); + +out: + if (rc < 0) + ipe_free_policy(p); + kfree(copy); + return (rc < 0) ? rc : len; +} + +static const struct file_operations np_fops = { + .write = new_policy, +}; + +static const struct file_operations audit_fops = { + .write = setaudit, + .read = getaudit, +}; + +static const struct file_operations enforce_fops = { + .write = setenforce, + .read = getenforce, +}; + +/** + * ipe_init_securityfs() - Initialize IPE's securityfs tree at fsinit. + * + * Return: %0 on success. If an error occurs, the function will return + * the -errno. + */ +static int __init ipe_init_securityfs(void) +{ + int rc = 0; + struct ipe_policy *ap; + + if (!ipe_enabled) + return -EOPNOTSUPP; + + root = securityfs_create_dir("ipe", NULL); + if (IS_ERR(root)) { + rc = PTR_ERR(root); + goto err; + } + + audit_node = securityfs_create_file("success_audit", 0600, root, + NULL, &audit_fops); + if (IS_ERR(audit_node)) { + rc = PTR_ERR(audit_node); + goto err; + } + + enforce_node = securityfs_create_file("enforce", 0600, root, NULL, + &enforce_fops); + if (IS_ERR(enforce_node)) { + rc = PTR_ERR(enforce_node); + goto err; + } + + policy_root = securityfs_create_dir("policies", root); + if (IS_ERR(policy_root)) { + rc = PTR_ERR(policy_root); + goto err; + } + + ap = rcu_access_pointer(ipe_active_policy); + if (ap) { + rc = ipe_new_policyfs_node(ap); + if (rc) + goto err; + } + + np = securityfs_create_file("new_policy", 0200, root, NULL, &np_fops); + if (IS_ERR(np)) { + rc = PTR_ERR(np); + goto err; + } + + return 0; +err: + securityfs_remove(np); + securityfs_remove(policy_root); + securityfs_remove(enforce_node); + securityfs_remove(audit_node); + securityfs_remove(root); + return rc; +} + +fs_initcall(ipe_init_securityfs); diff --git a/security/ipe/fs.h b/security/ipe/fs.h new file mode 100644 index 000000000000..0141ae8e86ec --- /dev/null +++ b/security/ipe/fs.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#ifndef _IPE_FS_H +#define _IPE_FS_H + +#include "policy.h" + +extern struct dentry *policy_root __ro_after_init; + +int ipe_new_policyfs_node(struct ipe_policy *p); +void ipe_del_policyfs_node(struct ipe_policy *p); + +#endif /* _IPE_FS_H */ diff --git a/security/ipe/hooks.c b/security/ipe/hooks.c new file mode 100644 index 000000000000..d0323b81cd8f --- /dev/null +++ b/security/ipe/hooks.c @@ -0,0 +1,314 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <linux/fs.h> +#include <linux/fs_struct.h> +#include <linux/types.h> +#include <linux/binfmts.h> +#include <linux/mman.h> +#include <linux/blk_types.h> + +#include "ipe.h" +#include "hooks.h" +#include "eval.h" +#include "digest.h" + +/** + * ipe_bprm_check_security() - ipe security hook function for bprm check. + * @bprm: Supplies a pointer to a linux_binprm structure to source the file + * being evaluated. + * + * This LSM hook is called when a binary is loaded through the exec + * family of system calls. + * + * Return: + * * %0 - Success + * * %-EACCES - Did not pass IPE policy + */ +int ipe_bprm_check_security(struct linux_binprm *bprm) +{ + struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT; + + ipe_build_eval_ctx(&ctx, bprm->file, IPE_OP_EXEC, IPE_HOOK_BPRM_CHECK); + return ipe_evaluate_event(&ctx); +} + +/** + * ipe_mmap_file() - ipe security hook function for mmap check. + * @f: File being mmap'd. Can be NULL in the case of anonymous memory. + * @reqprot: The requested protection on the mmap, passed from usermode. + * @prot: The effective protection on the mmap, resolved from reqprot and + * system configuration. + * @flags: Unused. + * + * This hook is called when a file is loaded through the mmap + * family of system calls. + * + * Return: + * * %0 - Success + * * %-EACCES - Did not pass IPE policy + */ +int ipe_mmap_file(struct file *f, unsigned long reqprot __always_unused, + unsigned long prot, unsigned long flags) +{ + struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT; + + if (prot & PROT_EXEC) { + ipe_build_eval_ctx(&ctx, f, IPE_OP_EXEC, IPE_HOOK_MMAP); + return ipe_evaluate_event(&ctx); + } + + return 0; +} + +/** + * ipe_file_mprotect() - ipe security hook function for mprotect check. + * @vma: Existing virtual memory area created by mmap or similar. + * @reqprot: The requested protection on the mmap, passed from usermode. + * @prot: The effective protection on the mmap, resolved from reqprot and + * system configuration. + * + * This LSM hook is called when a mmap'd region of memory is changing + * its protections via mprotect. + * + * Return: + * * %0 - Success + * * %-EACCES - Did not pass IPE policy + */ +int ipe_file_mprotect(struct vm_area_struct *vma, + unsigned long reqprot __always_unused, + unsigned long prot) +{ + struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT; + + /* Already Executable */ + if (vma->vm_flags & VM_EXEC) + return 0; + + if (prot & PROT_EXEC) { + ipe_build_eval_ctx(&ctx, vma->vm_file, IPE_OP_EXEC, IPE_HOOK_MPROTECT); + return ipe_evaluate_event(&ctx); + } + + return 0; +} + +/** + * ipe_kernel_read_file() - ipe security hook function for kernel read. + * @file: Supplies a pointer to the file structure being read in from disk. + * @id: Supplies the enumeration identifying the purpose of the read. + * @contents: Unused. + * + * This LSM hook is called when a file is read from disk in the kernel. + * + * Return: + * * %0 - Success + * * %-EACCES - Did not pass IPE policy + */ +int ipe_kernel_read_file(struct file *file, enum kernel_read_file_id id, + bool contents) +{ + struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT; + enum ipe_op_type op; + + switch (id) { + case READING_FIRMWARE: + op = IPE_OP_FIRMWARE; + break; + case READING_MODULE: + op = IPE_OP_KERNEL_MODULE; + break; + case READING_KEXEC_INITRAMFS: + op = IPE_OP_KEXEC_INITRAMFS; + break; + case READING_KEXEC_IMAGE: + op = IPE_OP_KEXEC_IMAGE; + break; + case READING_POLICY: + op = IPE_OP_POLICY; + break; + case READING_X509_CERTIFICATE: + op = IPE_OP_X509; + break; + default: + op = IPE_OP_INVALID; + WARN(1, "no rule setup for kernel_read_file enum %d", id); + } + + ipe_build_eval_ctx(&ctx, file, op, IPE_HOOK_KERNEL_READ); + return ipe_evaluate_event(&ctx); +} + +/** + * ipe_kernel_load_data() - ipe security hook function for kernel load data. + * @id: Supplies the enumeration identifying the purpose of the load. + * @contents: Unused. + * + * This LSM hook is called when a data buffer provided by userspace is loading + * into the kernel. + * + * Return: + * * %0 - Success + * * %-EACCES - Did not pass IPE policy + */ +int ipe_kernel_load_data(enum kernel_load_data_id id, bool contents) +{ + struct ipe_eval_ctx ctx = IPE_EVAL_CTX_INIT; + enum ipe_op_type op; + + switch (id) { + case LOADING_FIRMWARE: + op = IPE_OP_FIRMWARE; + break; + case LOADING_MODULE: + op = IPE_OP_KERNEL_MODULE; + break; + case LOADING_KEXEC_INITRAMFS: + op = IPE_OP_KEXEC_INITRAMFS; + break; + case LOADING_KEXEC_IMAGE: + op = IPE_OP_KEXEC_IMAGE; + break; + case LOADING_POLICY: + op = IPE_OP_POLICY; + break; + case LOADING_X509_CERTIFICATE: + op = IPE_OP_X509; + break; + default: + op = IPE_OP_INVALID; + WARN(1, "no rule setup for kernel_load_data enum %d", id); + } + + ipe_build_eval_ctx(&ctx, NULL, op, IPE_HOOK_KERNEL_LOAD); + return ipe_evaluate_event(&ctx); +} + +/** + * ipe_unpack_initramfs() - Mark the current rootfs as initramfs. + */ +void ipe_unpack_initramfs(void) +{ + ipe_sb(current->fs->root.mnt->mnt_sb)->initramfs = true; +} + +#ifdef CONFIG_IPE_PROP_DM_VERITY +/** + * ipe_bdev_free_security() - Free IPE's LSM blob of block_devices. + * @bdev: Supplies a pointer to a block_device that contains the structure + * to free. + */ +void ipe_bdev_free_security(struct block_device *bdev) +{ + struct ipe_bdev *blob = ipe_bdev(bdev); + + ipe_digest_free(blob->root_hash); +} + +#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE +static void ipe_set_dmverity_signature(struct ipe_bdev *blob, + const void *value, + size_t size) +{ + blob->dm_verity_signed = size > 0 && value; +} +#else +static inline void ipe_set_dmverity_signature(struct ipe_bdev *blob, + const void *value, + size_t size) +{ +} +#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */ + +/** + * ipe_bdev_setintegrity() - Save integrity data from a bdev to IPE's LSM blob. + * @bdev: Supplies a pointer to a block_device that contains the LSM blob. + * @type: Supplies the integrity type. + * @value: Supplies the value to store. + * @size: The size of @value. + * + * This hook is currently used to save dm-verity's root hash or the existence + * of a validated signed dm-verity root hash into LSM blob. + * + * Return: %0 on success. If an error occurs, the function will return the + * -errno. + */ +int ipe_bdev_setintegrity(struct block_device *bdev, enum lsm_integrity_type type, + const void *value, size_t size) +{ + const struct dm_verity_digest *digest = NULL; + struct ipe_bdev *blob = ipe_bdev(bdev); + struct digest_info *info = NULL; + + if (type == LSM_INT_DMVERITY_SIG_VALID) { + ipe_set_dmverity_signature(blob, value, size); + + return 0; + } + + if (type != LSM_INT_DMVERITY_ROOTHASH) + return -EINVAL; + + if (!value) { + ipe_digest_free(blob->root_hash); + blob->root_hash = NULL; + + return 0; + } + digest = value; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + info->digest = kmemdup(digest->digest, digest->digest_len, GFP_KERNEL); + if (!info->digest) + goto err; + + info->alg = kstrdup(digest->alg, GFP_KERNEL); + if (!info->alg) + goto err; + + info->digest_len = digest->digest_len; + + ipe_digest_free(blob->root_hash); + blob->root_hash = info; + + return 0; +err: + ipe_digest_free(info); + + return -ENOMEM; +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG +/** + * ipe_inode_setintegrity() - save integrity data from a inode to IPE's LSM blob. + * @inode: The inode to source the security blob from. + * @type: Supplies the integrity type. + * @value: The value to be stored. + * @size: The size of @value. + * + * This hook is currently used to save the existence of a validated fs-verity + * builtin signature into LSM blob. + * + * Return: %0 on success. If an error occurs, the function will return the + * -errno. + */ +int ipe_inode_setintegrity(const struct inode *inode, + enum lsm_integrity_type type, + const void *value, size_t size) +{ + struct ipe_inode *inode_sec = ipe_inode(inode); + + if (type == LSM_INT_FSVERITY_BUILTINSIG_VALID) { + inode_sec->fs_verity_signed = size > 0 && value; + return 0; + } + + return -EINVAL; +} +#endif /* CONFIG_CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ diff --git a/security/ipe/hooks.h b/security/ipe/hooks.h new file mode 100644 index 000000000000..38d4a387d039 --- /dev/null +++ b/security/ipe/hooks.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ +#ifndef _IPE_HOOKS_H +#define _IPE_HOOKS_H + +#include <linux/fs.h> +#include <linux/binfmts.h> +#include <linux/security.h> +#include <linux/blk_types.h> +#include <linux/fsverity.h> + +enum ipe_hook_type { + IPE_HOOK_BPRM_CHECK = 0, + IPE_HOOK_MMAP, + IPE_HOOK_MPROTECT, + IPE_HOOK_KERNEL_READ, + IPE_HOOK_KERNEL_LOAD, + __IPE_HOOK_MAX +}; + +#define IPE_HOOK_INVALID __IPE_HOOK_MAX + +int ipe_bprm_check_security(struct linux_binprm *bprm); + +int ipe_mmap_file(struct file *f, unsigned long reqprot, unsigned long prot, + unsigned long flags); + +int ipe_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, + unsigned long prot); + +int ipe_kernel_read_file(struct file *file, enum kernel_read_file_id id, + bool contents); + +int ipe_kernel_load_data(enum kernel_load_data_id id, bool contents); + +void ipe_unpack_initramfs(void); + +#ifdef CONFIG_IPE_PROP_DM_VERITY +void ipe_bdev_free_security(struct block_device *bdev); + +int ipe_bdev_setintegrity(struct block_device *bdev, enum lsm_integrity_type type, + const void *value, size_t len); +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG +int ipe_inode_setintegrity(const struct inode *inode, enum lsm_integrity_type type, + const void *value, size_t size); +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ + +#endif /* _IPE_HOOKS_H */ diff --git a/security/ipe/ipe.c b/security/ipe/ipe.c new file mode 100644 index 000000000000..4317134cb0da --- /dev/null +++ b/security/ipe/ipe.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ +#include <uapi/linux/lsm.h> + +#include "ipe.h" +#include "eval.h" +#include "hooks.h" + +extern const char *const ipe_boot_policy; +bool ipe_enabled; + +static struct lsm_blob_sizes ipe_blobs __ro_after_init = { + .lbs_superblock = sizeof(struct ipe_superblock), +#ifdef CONFIG_IPE_PROP_DM_VERITY + .lbs_bdev = sizeof(struct ipe_bdev), +#endif /* CONFIG_IPE_PROP_DM_VERITY */ +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG + .lbs_inode = sizeof(struct ipe_inode), +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ +}; + +static const struct lsm_id ipe_lsmid = { + .name = "ipe", + .id = LSM_ID_IPE, +}; + +struct ipe_superblock *ipe_sb(const struct super_block *sb) +{ + return sb->s_security + ipe_blobs.lbs_superblock; +} + +#ifdef CONFIG_IPE_PROP_DM_VERITY +struct ipe_bdev *ipe_bdev(struct block_device *b) +{ + return b->bd_security + ipe_blobs.lbs_bdev; +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG +struct ipe_inode *ipe_inode(const struct inode *inode) +{ + return inode->i_security + ipe_blobs.lbs_inode; +} +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ + +static struct security_hook_list ipe_hooks[] __ro_after_init = { + LSM_HOOK_INIT(bprm_check_security, ipe_bprm_check_security), + LSM_HOOK_INIT(mmap_file, ipe_mmap_file), + LSM_HOOK_INIT(file_mprotect, ipe_file_mprotect), + LSM_HOOK_INIT(kernel_read_file, ipe_kernel_read_file), + LSM_HOOK_INIT(kernel_load_data, ipe_kernel_load_data), + LSM_HOOK_INIT(initramfs_populated, ipe_unpack_initramfs), +#ifdef CONFIG_IPE_PROP_DM_VERITY + LSM_HOOK_INIT(bdev_free_security, ipe_bdev_free_security), + LSM_HOOK_INIT(bdev_setintegrity, ipe_bdev_setintegrity), +#endif /* CONFIG_IPE_PROP_DM_VERITY */ +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG + LSM_HOOK_INIT(inode_setintegrity, ipe_inode_setintegrity), +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ +}; + +/** + * ipe_init() - Entry point of IPE. + * + * This is called at LSM init, which happens occurs early during kernel + * start up. During this phase, IPE registers its hooks and loads the + * builtin boot policy. + * + * Return: + * * %0 - OK + * * %-ENOMEM - Out of memory (OOM) + */ +static int __init ipe_init(void) +{ + struct ipe_policy *p = NULL; + + security_add_hooks(ipe_hooks, ARRAY_SIZE(ipe_hooks), &ipe_lsmid); + ipe_enabled = true; + + if (ipe_boot_policy) { + p = ipe_new_policy(ipe_boot_policy, strlen(ipe_boot_policy), + NULL, 0); + if (IS_ERR(p)) + return PTR_ERR(p); + + rcu_assign_pointer(ipe_active_policy, p); + } + + return 0; +} + +DEFINE_LSM(ipe) = { + .name = "ipe", + .init = ipe_init, + .blobs = &ipe_blobs, +}; diff --git a/security/ipe/ipe.h b/security/ipe/ipe.h new file mode 100644 index 000000000000..fb37513812dd --- /dev/null +++ b/security/ipe/ipe.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#ifndef _IPE_H +#define _IPE_H + +#ifdef pr_fmt +#undef pr_fmt +#endif +#define pr_fmt(fmt) "ipe: " fmt + +#include <linux/lsm_hooks.h> +struct ipe_superblock *ipe_sb(const struct super_block *sb); + +extern bool ipe_enabled; + +#ifdef CONFIG_IPE_PROP_DM_VERITY +struct ipe_bdev *ipe_bdev(struct block_device *b); +#endif /* CONFIG_IPE_PROP_DM_VERITY */ +#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG +struct ipe_inode *ipe_inode(const struct inode *inode); +#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */ + +#endif /* _IPE_H */ diff --git a/security/ipe/policy.c b/security/ipe/policy.c new file mode 100644 index 000000000000..d8e7db857a2e --- /dev/null +++ b/security/ipe/policy.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <linux/errno.h> +#include <linux/verification.h> + +#include "ipe.h" +#include "eval.h" +#include "fs.h" +#include "policy.h" +#include "policy_parser.h" +#include "audit.h" + +/* lock for synchronizing writers across ipe policy */ +DEFINE_MUTEX(ipe_policy_lock); + +/** + * ver_to_u64() - Convert an internal ipe_policy_version to a u64. + * @p: Policy to extract the version from. + * + * Bits (LSB is index 0): + * [48,32] -> Major + * [32,16] -> Minor + * [16, 0] -> Revision + * + * Return: u64 version of the embedded version structure. + */ +static inline u64 ver_to_u64(const struct ipe_policy *const p) +{ + u64 r; + + r = (((u64)p->parsed->version.major) << 32) + | (((u64)p->parsed->version.minor) << 16) + | ((u64)(p->parsed->version.rev)); + + return r; +} + +/** + * ipe_free_policy() - Deallocate a given IPE policy. + * @p: Supplies the policy to free. + * + * Safe to call on IS_ERR/NULL. + */ +void ipe_free_policy(struct ipe_policy *p) +{ + if (IS_ERR_OR_NULL(p)) + return; + + ipe_del_policyfs_node(p); + ipe_free_parsed_policy(p->parsed); + /* + * p->text is allocated only when p->pkcs7 is not NULL + * otherwise it points to the plaintext data inside the pkcs7 + */ + if (!p->pkcs7) + kfree(p->text); + kfree(p->pkcs7); + kfree(p); +} + +static int set_pkcs7_data(void *ctx, const void *data, size_t len, + size_t asn1hdrlen __always_unused) +{ + struct ipe_policy *p = ctx; + + p->text = (const char *)data; + p->textlen = len; + + return 0; +} + +/** + * ipe_update_policy() - parse a new policy and replace old with it. + * @root: Supplies a pointer to the securityfs inode saved the policy. + * @text: Supplies a pointer to the plain text policy. + * @textlen: Supplies the length of @text. + * @pkcs7: Supplies a pointer to a buffer containing a pkcs7 message. + * @pkcs7len: Supplies the length of @pkcs7len. + * + * @text/@textlen is mutually exclusive with @pkcs7/@pkcs7len - see + * ipe_new_policy. + * + * Context: Requires root->i_rwsem to be held. + * Return: %0 on success. If an error occurs, the function will return + * the -errno. + */ +int ipe_update_policy(struct inode *root, const char *text, size_t textlen, + const char *pkcs7, size_t pkcs7len) +{ + struct ipe_policy *old, *ap, *new = NULL; + int rc = 0; + + old = (struct ipe_policy *)root->i_private; + if (!old) + return -ENOENT; + + new = ipe_new_policy(text, textlen, pkcs7, pkcs7len); + if (IS_ERR(new)) + return PTR_ERR(new); + + if (strcmp(new->parsed->name, old->parsed->name)) { + rc = -EINVAL; + goto err; + } + + if (ver_to_u64(old) > ver_to_u64(new)) { + rc = -EINVAL; + goto err; + } + + root->i_private = new; + swap(new->policyfs, old->policyfs); + ipe_audit_policy_load(new); + + mutex_lock(&ipe_policy_lock); + ap = rcu_dereference_protected(ipe_active_policy, + lockdep_is_held(&ipe_policy_lock)); + if (old == ap) { + rcu_assign_pointer(ipe_active_policy, new); + mutex_unlock(&ipe_policy_lock); + ipe_audit_policy_activation(old, new); + } else { + mutex_unlock(&ipe_policy_lock); + } + synchronize_rcu(); + ipe_free_policy(old); + + return 0; +err: + ipe_free_policy(new); + return rc; +} + +/** + * ipe_new_policy() - Allocate and parse an ipe_policy structure. + * + * @text: Supplies a pointer to the plain-text policy to parse. + * @textlen: Supplies the length of @text. + * @pkcs7: Supplies a pointer to a pkcs7-signed IPE policy. + * @pkcs7len: Supplies the length of @pkcs7. + * + * @text/@textlen Should be NULL/0 if @pkcs7/@pkcs7len is set. + * + * Return: + * * a pointer to the ipe_policy structure - Success + * * %-EBADMSG - Policy is invalid + * * %-ENOMEM - Out of memory (OOM) + * * %-ERANGE - Policy version number overflow + * * %-EINVAL - Policy version parsing error + */ +struct ipe_policy *ipe_new_policy(const char *text, size_t textlen, + const char *pkcs7, size_t pkcs7len) +{ + struct ipe_policy *new = NULL; + int rc = 0; + + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return ERR_PTR(-ENOMEM); + + if (!text) { + new->pkcs7len = pkcs7len; + new->pkcs7 = kmemdup(pkcs7, pkcs7len, GFP_KERNEL); + if (!new->pkcs7) { + rc = -ENOMEM; + goto err; + } + + rc = verify_pkcs7_signature(NULL, 0, new->pkcs7, pkcs7len, NULL, + VERIFYING_UNSPECIFIED_SIGNATURE, + set_pkcs7_data, new); + if (rc) + goto err; + } else { + new->textlen = textlen; + new->text = kstrdup(text, GFP_KERNEL); + if (!new->text) { + rc = -ENOMEM; + goto err; + } + } + + rc = ipe_parse_policy(new); + if (rc) + goto err; + + return new; +err: + ipe_free_policy(new); + return ERR_PTR(rc); +} + +/** + * ipe_set_active_pol() - Make @p the active policy. + * @p: Supplies a pointer to the policy to make active. + * + * Context: Requires root->i_rwsem, which i_private has the policy, to be held. + * Return: + * * %0 - Success + * * %-EINVAL - New active policy version is invalid + */ +int ipe_set_active_pol(const struct ipe_policy *p) +{ + struct ipe_policy *ap = NULL; + + mutex_lock(&ipe_policy_lock); + + ap = rcu_dereference_protected(ipe_active_policy, + lockdep_is_held(&ipe_policy_lock)); + if (ap == p) { + mutex_unlock(&ipe_policy_lock); + return 0; + } + if (ap && ver_to_u64(ap) > ver_to_u64(p)) { + mutex_unlock(&ipe_policy_lock); + return -EINVAL; + } + + rcu_assign_pointer(ipe_active_policy, p); + ipe_audit_policy_activation(ap, p); + mutex_unlock(&ipe_policy_lock); + + return 0; +} diff --git a/security/ipe/policy.h b/security/ipe/policy.h new file mode 100644 index 000000000000..5bfbdbddeef8 --- /dev/null +++ b/security/ipe/policy.h @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ +#ifndef _IPE_POLICY_H +#define _IPE_POLICY_H + +#include <linux/list.h> +#include <linux/types.h> +#include <linux/fs.h> + +enum ipe_op_type { + IPE_OP_EXEC = 0, + IPE_OP_FIRMWARE, + IPE_OP_KERNEL_MODULE, + IPE_OP_KEXEC_IMAGE, + IPE_OP_KEXEC_INITRAMFS, + IPE_OP_POLICY, + IPE_OP_X509, + __IPE_OP_MAX, +}; + +#define IPE_OP_INVALID __IPE_OP_MAX + +enum ipe_action_type { + IPE_ACTION_ALLOW = 0, + IPE_ACTION_DENY, + __IPE_ACTION_MAX +}; + +#define IPE_ACTION_INVALID __IPE_ACTION_MAX + +enum ipe_prop_type { + IPE_PROP_BOOT_VERIFIED_FALSE, + IPE_PROP_BOOT_VERIFIED_TRUE, + IPE_PROP_DMV_ROOTHASH, + IPE_PROP_DMV_SIG_FALSE, + IPE_PROP_DMV_SIG_TRUE, + IPE_PROP_FSV_DIGEST, + IPE_PROP_FSV_SIG_FALSE, + IPE_PROP_FSV_SIG_TRUE, + __IPE_PROP_MAX +}; + +#define IPE_PROP_INVALID __IPE_PROP_MAX + +struct ipe_prop { + struct list_head next; + enum ipe_prop_type type; + void *value; +}; + +struct ipe_rule { + enum ipe_op_type op; + enum ipe_action_type action; + struct list_head props; + struct list_head next; +}; + +struct ipe_op_table { + struct list_head rules; + enum ipe_action_type default_action; +}; + +struct ipe_parsed_policy { + const char *name; + struct { + u16 major; + u16 minor; + u16 rev; + } version; + + enum ipe_action_type global_default_action; + + struct ipe_op_table rules[__IPE_OP_MAX]; +}; + +struct ipe_policy { + const char *pkcs7; + size_t pkcs7len; + + const char *text; + size_t textlen; + + struct ipe_parsed_policy *parsed; + + struct dentry *policyfs; +}; + +struct ipe_policy *ipe_new_policy(const char *text, size_t textlen, + const char *pkcs7, size_t pkcs7len); +void ipe_free_policy(struct ipe_policy *pol); +int ipe_update_policy(struct inode *root, const char *text, size_t textlen, + const char *pkcs7, size_t pkcs7len); +int ipe_set_active_pol(const struct ipe_policy *p); +extern struct mutex ipe_policy_lock; + +#endif /* _IPE_POLICY_H */ diff --git a/security/ipe/policy_fs.c b/security/ipe/policy_fs.c new file mode 100644 index 000000000000..3bcd8cbd09df --- /dev/null +++ b/security/ipe/policy_fs.c @@ -0,0 +1,472 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ +#include <linux/fs.h> +#include <linux/namei.h> +#include <linux/types.h> +#include <linux/dcache.h> +#include <linux/security.h> + +#include "ipe.h" +#include "policy.h" +#include "eval.h" +#include "fs.h" + +#define MAX_VERSION_SIZE ARRAY_SIZE("65535.65535.65535") + +/** + * ipefs_file - defines a file in securityfs. + */ +struct ipefs_file { + const char *name; + umode_t access; + const struct file_operations *fops; +}; + +/** + * read_pkcs7() - Read handler for "ipe/policies/$name/pkcs7". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * @data will be populated with the pkcs7 blob representing the policy + * on success. If the policy is unsigned (like the boot policy), this + * will return -ENOENT. + * + * Return: + * * Length of buffer written - Success + * * %-ENOENT - Policy initializing/deleted or is unsigned + */ +static ssize_t read_pkcs7(struct file *f, char __user *data, + size_t len, loff_t *offset) +{ + const struct ipe_policy *p = NULL; + struct inode *root = NULL; + int rc = 0; + + root = d_inode(f->f_path.dentry->d_parent); + + inode_lock_shared(root); + p = (struct ipe_policy *)root->i_private; + if (!p) { + rc = -ENOENT; + goto out; + } + + if (!p->pkcs7) { + rc = -ENOENT; + goto out; + } + + rc = simple_read_from_buffer(data, len, offset, p->pkcs7, p->pkcs7len); + +out: + inode_unlock_shared(root); + + return rc; +} + +/** + * read_policy() - Read handler for "ipe/policies/$name/policy". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * @data will be populated with the plain-text version of the policy + * on success. + * + * Return: + * * Length of buffer written - Success + * * %-ENOENT - Policy initializing/deleted + */ +static ssize_t read_policy(struct file *f, char __user *data, + size_t len, loff_t *offset) +{ + const struct ipe_policy *p = NULL; + struct inode *root = NULL; + int rc = 0; + + root = d_inode(f->f_path.dentry->d_parent); + + inode_lock_shared(root); + p = (struct ipe_policy *)root->i_private; + if (!p) { + rc = -ENOENT; + goto out; + } + + rc = simple_read_from_buffer(data, len, offset, p->text, p->textlen); + +out: + inode_unlock_shared(root); + + return rc; +} + +/** + * read_name() - Read handler for "ipe/policies/$name/name". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * @data will be populated with the policy_name attribute on success. + * + * Return: + * * Length of buffer written - Success + * * %-ENOENT - Policy initializing/deleted + */ +static ssize_t read_name(struct file *f, char __user *data, + size_t len, loff_t *offset) +{ + const struct ipe_policy *p = NULL; + struct inode *root = NULL; + int rc = 0; + + root = d_inode(f->f_path.dentry->d_parent); + + inode_lock_shared(root); + p = (struct ipe_policy *)root->i_private; + if (!p) { + rc = -ENOENT; + goto out; + } + + rc = simple_read_from_buffer(data, len, offset, p->parsed->name, + strlen(p->parsed->name)); + +out: + inode_unlock_shared(root); + + return rc; +} + +/** + * read_version() - Read handler for "ipe/policies/$name/version". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * @data will be populated with the version string on success. + * + * Return: + * * Length of buffer written - Success + * * %-ENOENT - Policy initializing/deleted + */ +static ssize_t read_version(struct file *f, char __user *data, + size_t len, loff_t *offset) +{ + char buffer[MAX_VERSION_SIZE] = { 0 }; + const struct ipe_policy *p = NULL; + struct inode *root = NULL; + size_t strsize = 0; + ssize_t rc = 0; + + root = d_inode(f->f_path.dentry->d_parent); + + inode_lock_shared(root); + p = (struct ipe_policy *)root->i_private; + if (!p) { + rc = -ENOENT; + goto out; + } + + strsize = scnprintf(buffer, ARRAY_SIZE(buffer), "%hu.%hu.%hu", + p->parsed->version.major, p->parsed->version.minor, + p->parsed->version.rev); + + rc = simple_read_from_buffer(data, len, offset, buffer, strsize); + +out: + inode_unlock_shared(root); + + return rc; +} + +/** + * setactive() - Write handler for "ipe/policies/$name/active". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * Return: + * * Length of buffer written - Success + * * %-EPERM - Insufficient permission + * * %-EINVAL - Invalid input + * * %-ENOENT - Policy initializing/deleted + */ +static ssize_t setactive(struct file *f, const char __user *data, + size_t len, loff_t *offset) +{ + const struct ipe_policy *p = NULL; + struct inode *root = NULL; + bool value = false; + int rc = 0; + + if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + rc = kstrtobool_from_user(data, len, &value); + if (rc) + return rc; + + if (!value) + return -EINVAL; + + root = d_inode(f->f_path.dentry->d_parent); + inode_lock(root); + + p = (struct ipe_policy *)root->i_private; + if (!p) { + rc = -ENOENT; + goto out; + } + + rc = ipe_set_active_pol(p); + +out: + inode_unlock(root); + return (rc < 0) ? rc : len; +} + +/** + * getactive() - Read handler for "ipe/policies/$name/active". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * @data will be populated with the 1 or 0 depending on if the + * corresponding policy is active. + * + * Return: + * * Length of buffer written - Success + * * %-ENOENT - Policy initializing/deleted + */ +static ssize_t getactive(struct file *f, char __user *data, + size_t len, loff_t *offset) +{ + const struct ipe_policy *p = NULL; + struct inode *root = NULL; + const char *str; + int rc = 0; + + root = d_inode(f->f_path.dentry->d_parent); + + inode_lock_shared(root); + p = (struct ipe_policy *)root->i_private; + if (!p) { + inode_unlock_shared(root); + return -ENOENT; + } + inode_unlock_shared(root); + + str = (p == rcu_access_pointer(ipe_active_policy)) ? "1" : "0"; + rc = simple_read_from_buffer(data, len, offset, str, 1); + + return rc; +} + +/** + * update_policy() - Write handler for "ipe/policies/$name/update". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * On success this updates the policy represented by $name, + * in-place. + * + * Return: Length of buffer written on success. If an error occurs, + * the function will return the -errno. + */ +static ssize_t update_policy(struct file *f, const char __user *data, + size_t len, loff_t *offset) +{ + struct inode *root = NULL; + char *copy = NULL; + int rc = 0; + + if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + copy = memdup_user(data, len); + if (IS_ERR(copy)) + return PTR_ERR(copy); + + root = d_inode(f->f_path.dentry->d_parent); + inode_lock(root); + rc = ipe_update_policy(root, NULL, 0, copy, len); + inode_unlock(root); + + kfree(copy); + if (rc) + return rc; + + return len; +} + +/** + * delete_policy() - write handler for "ipe/policies/$name/delete". + * @f: Supplies a file structure representing the securityfs node. + * @data: Supplies a buffer passed to the write syscall. + * @len: Supplies the length of @data. + * @offset: unused. + * + * On success this deletes the policy represented by $name. + * + * Return: + * * Length of buffer written - Success + * * %-EPERM - Insufficient permission/deleting active policy + * * %-EINVAL - Invalid input + * * %-ENOENT - Policy initializing/deleted + */ +static ssize_t delete_policy(struct file *f, const char __user *data, + size_t len, loff_t *offset) +{ + struct ipe_policy *ap = NULL; + struct ipe_policy *p = NULL; + struct inode *root = NULL; + bool value = false; + int rc = 0; + + if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) + return -EPERM; + + rc = kstrtobool_from_user(data, len, &value); + if (rc) + return rc; + + if (!value) + return -EINVAL; + + root = d_inode(f->f_path.dentry->d_parent); + inode_lock(root); + p = (struct ipe_policy *)root->i_private; + if (!p) { + inode_unlock(root); + return -ENOENT; + } + + mutex_lock(&ipe_policy_lock); + ap = rcu_dereference_protected(ipe_active_policy, + lockdep_is_held(&ipe_policy_lock)); + if (p == ap) { + mutex_unlock(&ipe_policy_lock); + inode_unlock(root); + return -EPERM; + } + mutex_unlock(&ipe_policy_lock); + + root->i_private = NULL; + inode_unlock(root); + + synchronize_rcu(); + ipe_free_policy(p); + + return len; +} + +static const struct file_operations content_fops = { + .read = read_policy, +}; + +static const struct file_operations pkcs7_fops = { + .read = read_pkcs7, +}; + +static const struct file_operations name_fops = { + .read = read_name, +}; + +static const struct file_operations ver_fops = { + .read = read_version, +}; + +static const struct file_operations active_fops = { + .write = setactive, + .read = getactive, +}; + +static const struct file_operations update_fops = { + .write = update_policy, +}; + +static const struct file_operations delete_fops = { + .write = delete_policy, +}; + +/** + * policy_subdir - files under a policy subdirectory + */ +static const struct ipefs_file policy_subdir[] = { + { "pkcs7", 0444, &pkcs7_fops }, + { "policy", 0444, &content_fops }, + { "name", 0444, &name_fops }, + { "version", 0444, &ver_fops }, + { "active", 0600, &active_fops }, + { "update", 0200, &update_fops }, + { "delete", 0200, &delete_fops }, +}; + +/** + * ipe_del_policyfs_node() - Delete a securityfs entry for @p. + * @p: Supplies a pointer to the policy to delete a securityfs entry for. + */ +void ipe_del_policyfs_node(struct ipe_policy *p) +{ + securityfs_recursive_remove(p->policyfs); + p->policyfs = NULL; +} + +/** + * ipe_new_policyfs_node() - Create a securityfs entry for @p. + * @p: Supplies a pointer to the policy to create a securityfs entry for. + * + * Return: %0 on success. If an error occurs, the function will return + * the -errno. + */ +int ipe_new_policyfs_node(struct ipe_policy *p) +{ + const struct ipefs_file *f = NULL; + struct dentry *policyfs = NULL; + struct inode *root = NULL; + struct dentry *d = NULL; + size_t i = 0; + int rc = 0; + + if (p->policyfs) + return 0; + + policyfs = securityfs_create_dir(p->parsed->name, policy_root); + if (IS_ERR(policyfs)) + return PTR_ERR(policyfs); + + root = d_inode(policyfs); + + for (i = 0; i < ARRAY_SIZE(policy_subdir); ++i) { + f = &policy_subdir[i]; + + d = securityfs_create_file(f->name, f->access, policyfs, + NULL, f->fops); + if (IS_ERR(d)) { + rc = PTR_ERR(d); + goto err; + } + } + + inode_lock(root); + p->policyfs = policyfs; + root->i_private = p; + inode_unlock(root); + + return 0; +err: + securityfs_recursive_remove(policyfs); + return rc; +} diff --git a/security/ipe/policy_parser.c b/security/ipe/policy_parser.c new file mode 100644 index 000000000000..7f27e39931d6 --- /dev/null +++ b/security/ipe/policy_parser.c @@ -0,0 +1,559 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/parser.h> +#include <linux/types.h> +#include <linux/ctype.h> + +#include "policy.h" +#include "policy_parser.h" +#include "digest.h" + +#define START_COMMENT '#' +#define IPE_POLICY_DELIM " \t" +#define IPE_LINE_DELIM "\n\r" + +/** + * new_parsed_policy() - Allocate and initialize a parsed policy. + * + * Return: + * * a pointer to the ipe_parsed_policy structure - Success + * * %-ENOMEM - Out of memory (OOM) + */ +static struct ipe_parsed_policy *new_parsed_policy(void) +{ + struct ipe_parsed_policy *p = NULL; + struct ipe_op_table *t = NULL; + size_t i = 0; + + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return ERR_PTR(-ENOMEM); + + p->global_default_action = IPE_ACTION_INVALID; + + for (i = 0; i < ARRAY_SIZE(p->rules); ++i) { + t = &p->rules[i]; + + t->default_action = IPE_ACTION_INVALID; + INIT_LIST_HEAD(&t->rules); + } + + return p; +} + +/** + * remove_comment() - Truncate all chars following START_COMMENT in a string. + * + * @line: Supplies a policy line string for preprocessing. + */ +static void remove_comment(char *line) +{ + line = strchr(line, START_COMMENT); + + if (line) + *line = '\0'; +} + +/** + * remove_trailing_spaces() - Truncate all trailing spaces in a string. + * + * @line: Supplies a policy line string for preprocessing. + * + * Return: The length of truncated string. + */ +static size_t remove_trailing_spaces(char *line) +{ + size_t i = 0; + + i = strlen(line); + while (i > 0 && isspace(line[i - 1])) + i--; + + line[i] = '\0'; + + return i; +} + +/** + * parse_version() - Parse policy version. + * @ver: Supplies a version string to be parsed. + * @p: Supplies the partial parsed policy. + * + * Return: + * * %0 - Success + * * %-EBADMSG - Version string is invalid + * * %-ERANGE - Version number overflow + * * %-EINVAL - Parsing error + */ +static int parse_version(char *ver, struct ipe_parsed_policy *p) +{ + u16 *const cv[] = { &p->version.major, &p->version.minor, &p->version.rev }; + size_t sep_count = 0; + char *token; + int rc = 0; + + while ((token = strsep(&ver, ".")) != NULL) { + /* prevent overflow */ + if (sep_count >= ARRAY_SIZE(cv)) + return -EBADMSG; + + rc = kstrtou16(token, 10, cv[sep_count]); + if (rc) + return rc; + + ++sep_count; + } + + /* prevent underflow */ + if (sep_count != ARRAY_SIZE(cv)) + return -EBADMSG; + + return 0; +} + +enum header_opt { + IPE_HEADER_POLICY_NAME = 0, + IPE_HEADER_POLICY_VERSION, + __IPE_HEADER_MAX +}; + +static const match_table_t header_tokens = { + {IPE_HEADER_POLICY_NAME, "policy_name=%s"}, + {IPE_HEADER_POLICY_VERSION, "policy_version=%s"}, + {__IPE_HEADER_MAX, NULL} +}; + +/** + * parse_header() - Parse policy header information. + * @line: Supplies header line to be parsed. + * @p: Supplies the partial parsed policy. + * + * Return: + * * %0 - Success + * * %-EBADMSG - Header string is invalid + * * %-ENOMEM - Out of memory (OOM) + * * %-ERANGE - Version number overflow + * * %-EINVAL - Version parsing error + */ +static int parse_header(char *line, struct ipe_parsed_policy *p) +{ + substring_t args[MAX_OPT_ARGS]; + char *t, *ver = NULL; + size_t idx = 0; + int rc = 0; + + while ((t = strsep(&line, IPE_POLICY_DELIM)) != NULL) { + int token; + + if (*t == '\0') + continue; + if (idx >= __IPE_HEADER_MAX) { + rc = -EBADMSG; + goto out; + } + + token = match_token(t, header_tokens, args); + if (token != idx) { + rc = -EBADMSG; + goto out; + } + + switch (token) { + case IPE_HEADER_POLICY_NAME: + p->name = match_strdup(&args[0]); + if (!p->name) + rc = -ENOMEM; + break; + case IPE_HEADER_POLICY_VERSION: + ver = match_strdup(&args[0]); + if (!ver) { + rc = -ENOMEM; + break; + } + rc = parse_version(ver, p); + break; + default: + rc = -EBADMSG; + } + if (rc) + goto out; + ++idx; + } + + if (idx != __IPE_HEADER_MAX) + rc = -EBADMSG; + +out: + kfree(ver); + return rc; +} + +/** + * token_default() - Determine if the given token is "DEFAULT". + * @token: Supplies the token string to be compared. + * + * Return: + * * %false - The token is not "DEFAULT" + * * %true - The token is "DEFAULT" + */ +static bool token_default(char *token) +{ + return !strcmp(token, "DEFAULT"); +} + +/** + * free_rule() - Free the supplied ipe_rule struct. + * @r: Supplies the ipe_rule struct to be freed. + * + * Free a ipe_rule struct @r. Note @r must be removed from any lists before + * calling this function. + */ +static void free_rule(struct ipe_rule *r) +{ + struct ipe_prop *p, *t; + + if (IS_ERR_OR_NULL(r)) + return; + + list_for_each_entry_safe(p, t, &r->props, next) { + list_del(&p->next); + ipe_digest_free(p->value); + kfree(p); + } + + kfree(r); +} + +static const match_table_t operation_tokens = { + {IPE_OP_EXEC, "op=EXECUTE"}, + {IPE_OP_FIRMWARE, "op=FIRMWARE"}, + {IPE_OP_KERNEL_MODULE, "op=KMODULE"}, + {IPE_OP_KEXEC_IMAGE, "op=KEXEC_IMAGE"}, + {IPE_OP_KEXEC_INITRAMFS, "op=KEXEC_INITRAMFS"}, + {IPE_OP_POLICY, "op=POLICY"}, + {IPE_OP_X509, "op=X509_CERT"}, + {IPE_OP_INVALID, NULL} +}; + +/** + * parse_operation() - Parse the operation type given a token string. + * @t: Supplies the token string to be parsed. + * + * Return: The parsed operation type. + */ +static enum ipe_op_type parse_operation(char *t) +{ + substring_t args[MAX_OPT_ARGS]; + + return match_token(t, operation_tokens, args); +} + +static const match_table_t action_tokens = { + {IPE_ACTION_ALLOW, "action=ALLOW"}, + {IPE_ACTION_DENY, "action=DENY"}, + {IPE_ACTION_INVALID, NULL} +}; + +/** + * parse_action() - Parse the action type given a token string. + * @t: Supplies the token string to be parsed. + * + * Return: The parsed action type. + */ +static enum ipe_action_type parse_action(char *t) +{ + substring_t args[MAX_OPT_ARGS]; + + return match_token(t, action_tokens, args); +} + +static const match_table_t property_tokens = { + {IPE_PROP_BOOT_VERIFIED_FALSE, "boot_verified=FALSE"}, + {IPE_PROP_BOOT_VERIFIED_TRUE, "boot_verified=TRUE"}, + {IPE_PROP_DMV_ROOTHASH, "dmverity_roothash=%s"}, + {IPE_PROP_DMV_SIG_FALSE, "dmverity_signature=FALSE"}, + {IPE_PROP_DMV_SIG_TRUE, "dmverity_signature=TRUE"}, + {IPE_PROP_FSV_DIGEST, "fsverity_digest=%s"}, + {IPE_PROP_FSV_SIG_FALSE, "fsverity_signature=FALSE"}, + {IPE_PROP_FSV_SIG_TRUE, "fsverity_signature=TRUE"}, + {IPE_PROP_INVALID, NULL} +}; + +/** + * parse_property() - Parse a rule property given a token string. + * @t: Supplies the token string to be parsed. + * @r: Supplies the ipe_rule the parsed property will be associated with. + * + * This function parses and associates a property with an IPE rule based + * on a token string. + * + * Return: + * * %0 - Success + * * %-ENOMEM - Out of memory (OOM) + * * %-EBADMSG - The supplied token cannot be parsed + */ +static int parse_property(char *t, struct ipe_rule *r) +{ + substring_t args[MAX_OPT_ARGS]; + struct ipe_prop *p = NULL; + int rc = 0; + int token; + char *dup = NULL; + + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + + token = match_token(t, property_tokens, args); + + switch (token) { + case IPE_PROP_DMV_ROOTHASH: + case IPE_PROP_FSV_DIGEST: + dup = match_strdup(&args[0]); + if (!dup) { + rc = -ENOMEM; + goto err; + } + p->value = ipe_digest_parse(dup); + if (IS_ERR(p->value)) { + rc = PTR_ERR(p->value); + goto err; + } + fallthrough; + case IPE_PROP_BOOT_VERIFIED_FALSE: + case IPE_PROP_BOOT_VERIFIED_TRUE: + case IPE_PROP_DMV_SIG_FALSE: + case IPE_PROP_DMV_SIG_TRUE: + case IPE_PROP_FSV_SIG_FALSE: + case IPE_PROP_FSV_SIG_TRUE: + p->type = token; + break; + default: + rc = -EBADMSG; + break; + } + if (rc) + goto err; + list_add_tail(&p->next, &r->props); + +out: + kfree(dup); + return rc; +err: + kfree(p); + goto out; +} + +/** + * parse_rule() - parse a policy rule line. + * @line: Supplies rule line to be parsed. + * @p: Supplies the partial parsed policy. + * + * Return: + * * 0 - Success + * * %-ENOMEM - Out of memory (OOM) + * * %-EBADMSG - Policy syntax error + */ +static int parse_rule(char *line, struct ipe_parsed_policy *p) +{ + enum ipe_action_type action = IPE_ACTION_INVALID; + enum ipe_op_type op = IPE_OP_INVALID; + bool is_default_rule = false; + struct ipe_rule *r = NULL; + bool first_token = true; + bool op_parsed = false; + int rc = 0; + char *t; + + if (IS_ERR_OR_NULL(line)) + return -EBADMSG; + + r = kzalloc(sizeof(*r), GFP_KERNEL); + if (!r) + return -ENOMEM; + + INIT_LIST_HEAD(&r->next); + INIT_LIST_HEAD(&r->props); + + while (t = strsep(&line, IPE_POLICY_DELIM), line) { + if (*t == '\0') + continue; + if (first_token && token_default(t)) { + is_default_rule = true; + } else { + if (!op_parsed) { + op = parse_operation(t); + if (op == IPE_OP_INVALID) + rc = -EBADMSG; + else + op_parsed = true; + } else { + rc = parse_property(t, r); + } + } + + if (rc) + goto err; + first_token = false; + } + + action = parse_action(t); + if (action == IPE_ACTION_INVALID) { + rc = -EBADMSG; + goto err; + } + + if (is_default_rule) { + if (!list_empty(&r->props)) { + rc = -EBADMSG; + } else if (op == IPE_OP_INVALID) { + if (p->global_default_action != IPE_ACTION_INVALID) + rc = -EBADMSG; + else + p->global_default_action = action; + } else { + if (p->rules[op].default_action != IPE_ACTION_INVALID) + rc = -EBADMSG; + else + p->rules[op].default_action = action; + } + } else if (op != IPE_OP_INVALID && action != IPE_ACTION_INVALID) { + r->op = op; + r->action = action; + } else { + rc = -EBADMSG; + } + + if (rc) + goto err; + if (!is_default_rule) + list_add_tail(&r->next, &p->rules[op].rules); + else + free_rule(r); + + return rc; +err: + free_rule(r); + return rc; +} + +/** + * ipe_free_parsed_policy() - free a parsed policy structure. + * @p: Supplies the parsed policy. + */ +void ipe_free_parsed_policy(struct ipe_parsed_policy *p) +{ + struct ipe_rule *pp, *t; + size_t i = 0; + + if (IS_ERR_OR_NULL(p)) + return; + + for (i = 0; i < ARRAY_SIZE(p->rules); ++i) + list_for_each_entry_safe(pp, t, &p->rules[i].rules, next) { + list_del(&pp->next); + free_rule(pp); + } + + kfree(p->name); + kfree(p); +} + +/** + * validate_policy() - validate a parsed policy. + * @p: Supplies the fully parsed policy. + * + * Given a policy structure that was just parsed, validate that all + * operations have their default rules or a global default rule is set. + * + * Return: + * * %0 - Success + * * %-EBADMSG - Policy is invalid + */ +static int validate_policy(const struct ipe_parsed_policy *p) +{ + size_t i = 0; + + if (p->global_default_action != IPE_ACTION_INVALID) + return 0; + + for (i = 0; i < ARRAY_SIZE(p->rules); ++i) { + if (p->rules[i].default_action == IPE_ACTION_INVALID) + return -EBADMSG; + } + + return 0; +} + +/** + * ipe_parse_policy() - Given a string, parse the string into an IPE policy. + * @p: partially filled ipe_policy structure to populate with the result. + * it must have text and textlen set. + * + * Return: + * * %0 - Success + * * %-EBADMSG - Policy is invalid + * * %-ENOMEM - Out of Memory + * * %-ERANGE - Policy version number overflow + * * %-EINVAL - Policy version parsing error + */ +int ipe_parse_policy(struct ipe_policy *p) +{ + struct ipe_parsed_policy *pp = NULL; + char *policy = NULL, *dup = NULL; + bool header_parsed = false; + char *line = NULL; + size_t len; + int rc = 0; + + if (!p->textlen) + return -EBADMSG; + + policy = kmemdup_nul(p->text, p->textlen, GFP_KERNEL); + if (!policy) + return -ENOMEM; + dup = policy; + + pp = new_parsed_policy(); + if (IS_ERR(pp)) { + rc = PTR_ERR(pp); + goto out; + } + + while ((line = strsep(&policy, IPE_LINE_DELIM)) != NULL) { + remove_comment(line); + len = remove_trailing_spaces(line); + if (!len) + continue; + + if (!header_parsed) { + rc = parse_header(line, pp); + if (rc) + goto err; + header_parsed = true; + } else { + rc = parse_rule(line, pp); + if (rc) + goto err; + } + } + + if (!header_parsed || validate_policy(pp)) { + rc = -EBADMSG; + goto err; + } + + p->parsed = pp; + +out: + kfree(dup); + return rc; +err: + ipe_free_parsed_policy(pp); + goto out; +} diff --git a/security/ipe/policy_parser.h b/security/ipe/policy_parser.h new file mode 100644 index 000000000000..62b6209019a2 --- /dev/null +++ b/security/ipe/policy_parser.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ +#ifndef _IPE_POLICY_PARSER_H +#define _IPE_POLICY_PARSER_H + +int ipe_parse_policy(struct ipe_policy *p); +void ipe_free_parsed_policy(struct ipe_parsed_policy *p); + +#endif /* _IPE_POLICY_PARSER_H */ diff --git a/security/ipe/policy_tests.c b/security/ipe/policy_tests.c new file mode 100644 index 000000000000..89521f6b9994 --- /dev/null +++ b/security/ipe/policy_tests.c @@ -0,0 +1,296 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/list.h> +#include <kunit/test.h> +#include "policy.h" +struct policy_case { + const char *const policy; + int errno; + const char *const desc; +}; + +static const struct policy_case policy_cases[] = { + { + "policy_name=allowall policy_version=0.0.0\n" + "DEFAULT action=ALLOW", + 0, + "basic", + }, + { + "policy_name=trailing_comment policy_version=152.0.0 #This is comment\n" + "DEFAULT action=ALLOW", + 0, + "trailing comment", + }, + { + "policy_name=allowallnewline policy_version=0.2.0\n" + "DEFAULT action=ALLOW\n" + "\n", + 0, + "trailing newline", + }, + { + "policy_name=carriagereturnlinefeed policy_version=0.0.1\n" + "DEFAULT action=ALLOW\n" + "\r\n", + 0, + "clrf newline", + }, + { + "policy_name=whitespace policy_version=0.0.0\n" + "DEFAULT\taction=ALLOW\n" + " \t DEFAULT \t op=EXECUTE action=DENY\n" + "op=EXECUTE boot_verified=TRUE action=ALLOW\n" + "# this is a\tcomment\t\t\t\t\n" + "DEFAULT \t op=KMODULE\t\t\t action=DENY\r\n" + "op=KMODULE boot_verified=TRUE action=ALLOW\n", + 0, + "various whitespaces and nested default", + }, + { + "policy_name=boot_verified policy_version=-1236.0.0\n" + "DEFAULT\taction=ALLOW\n", + -EINVAL, + "negative version", + }, + { + "policy_name=$@!*&^%%\\:;{}() policy_version=0.0.0\n" + "DEFAULT action=ALLOW", + 0, + "special characters", + }, + { + "policy_name=test policy_version=999999.0.0\n" + "DEFAULT action=ALLOW", + -ERANGE, + "overflow version", + }, + { + "policy_name=test policy_version=255.0\n" + "DEFAULT action=ALLOW", + -EBADMSG, + "incomplete version", + }, + { + "policy_name=test policy_version=111.0.0.0\n" + "DEFAULT action=ALLOW", + -EBADMSG, + "extra version", + }, + { + "", + -EBADMSG, + "0-length policy", + }, + { + "policy_name=test\0policy_version=0.0.0\n" + "DEFAULT action=ALLOW", + -EBADMSG, + "random null in header", + }, + { + "policy_name=test policy_version=0.0.0\n" + "\0DEFAULT action=ALLOW", + -EBADMSG, + "incomplete policy from NULL", + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=DENY\n\0" + "op=EXECUTE dmverity_signature=TRUE action=ALLOW\n", + 0, + "NULL truncates policy", + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "op=EXECUTE dmverity_signature=abc action=ALLOW", + -EBADMSG, + "invalid property type", + }, + { + "DEFAULT action=ALLOW", + -EBADMSG, + "missing policy header", + }, + { + "policy_name=test policy_version=0.0.0\n", + -EBADMSG, + "missing default definition", + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "dmverity_signature=TRUE op=EXECUTE action=ALLOW", + -EBADMSG, + "invalid rule ordering" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "action=ALLOW op=EXECUTE dmverity_signature=TRUE", + -EBADMSG, + "invalid rule ordering (2)", + }, + { + "policy_name=test policy_version=0.0\n" + "DEFAULT action=ALLOW\n" + "op=EXECUTE dmverity_signature=TRUE action=ALLOW", + -EBADMSG, + "invalid version", + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "op=UNKNOWN dmverity_signature=TRUE action=ALLOW", + -EBADMSG, + "unknown operation", + }, + { + "policy_name=asdvpolicy_version=0.0.0\n" + "DEFAULT action=ALLOW\n", + -EBADMSG, + "missing space after policy name", + }, + { + "policy_name=test\xFF\xEF policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "op=EXECUTE dmverity_signature=TRUE action=ALLOW", + 0, + "expanded ascii", + }, + { + "policy_name=test\xFF\xEF policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "op=EXECUTE dmverity_roothash=GOOD_DOG action=ALLOW", + -EBADMSG, + "invalid property value (2)", + }, + { + "policy_name=test policy_version=0.0.0\n" + "policy_name=test policy_version=0.1.0\n" + "DEFAULT action=ALLOW", + -EBADMSG, + "double header" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "DEFAULT action=ALLOW\n", + -EBADMSG, + "double default" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "DEFAULT op=EXECUTE action=DENY\n" + "DEFAULT op=EXECUTE action=ALLOW\n", + -EBADMSG, + "double operation default" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "DEFAULT op=EXECUTE action=DEN\n", + -EBADMSG, + "invalid action value" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "DEFAULT op=EXECUTE action\n", + -EBADMSG, + "invalid action value (2)" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "UNKNOWN value=true\n", + -EBADMSG, + "unrecognized statement" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "op=EXECUTE dmverity_roothash=1c0d7ee1f8343b7fbe418378e8eb22c061d7dec7 action=DENY\n", + -EBADMSG, + "old-style digest" + }, + { + "policy_name=test policy_version=0.0.0\n" + "DEFAULT action=ALLOW\n" + "op=EXECUTE fsverity_digest=1c0d7ee1f8343b7fbe418378e8eb22c061d7dec7 action=DENY\n", + -EBADMSG, + "old-style digest" + } +}; + +static void pol_to_desc(const struct policy_case *c, char *desc) +{ + strscpy(desc, c->desc, KUNIT_PARAM_DESC_SIZE); +} + +KUNIT_ARRAY_PARAM(ipe_policies, policy_cases, pol_to_desc); + +/** + * ipe_parser_unsigned_test - Test the parser by passing unsigned policies. + * @test: Supplies a pointer to a kunit structure. + * + * This is called by the kunit harness. This test does not check the correctness + * of the policy, but ensures that errors are handled correctly. + */ +static void ipe_parser_unsigned_test(struct kunit *test) +{ + const struct policy_case *p = test->param_value; + struct ipe_policy *pol; + + pol = ipe_new_policy(p->policy, strlen(p->policy), NULL, 0); + + if (p->errno) { + KUNIT_EXPECT_EQ(test, PTR_ERR(pol), p->errno); + return; + } + + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pol); + KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pol->parsed); + KUNIT_EXPECT_STREQ(test, pol->text, p->policy); + KUNIT_EXPECT_PTR_EQ(test, NULL, pol->pkcs7); + KUNIT_EXPECT_EQ(test, 0, pol->pkcs7len); + + ipe_free_policy(pol); +} + +/** + * ipe_parser_widestring_test - Ensure parser fail on a wide string policy. + * @test: Supplies a pointer to a kunit structure. + * + * This is called by the kunit harness. + */ +static void ipe_parser_widestring_test(struct kunit *test) +{ + const unsigned short policy[] = L"policy_name=Test policy_version=0.0.0\n" + L"DEFAULT action=ALLOW"; + struct ipe_policy *pol = NULL; + + pol = ipe_new_policy((const char *)policy, (ARRAY_SIZE(policy) - 1) * 2, NULL, 0); + KUNIT_EXPECT_TRUE(test, IS_ERR_OR_NULL(pol)); + + ipe_free_policy(pol); +} + +static struct kunit_case ipe_parser_test_cases[] = { + KUNIT_CASE_PARAM(ipe_parser_unsigned_test, ipe_policies_gen_params), + KUNIT_CASE(ipe_parser_widestring_test), +}; + +static struct kunit_suite ipe_parser_test_suite = { + .name = "ipe-parser", + .test_cases = ipe_parser_test_cases, +}; + +kunit_test_suite(ipe_parser_test_suite); diff --git a/security/landlock/fs.c b/security/landlock/fs.c index 7877a64cc6b8..0804f76a67be 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -1207,13 +1207,16 @@ static int current_check_refer_path(struct dentry *const old_dentry, /* Inode hooks */ -static void hook_inode_free_security(struct inode *const inode) +static void hook_inode_free_security_rcu(void *inode_security) { + struct landlock_inode_security *inode_sec; + /* * All inodes must already have been untied from their object by * release_inode() or hook_sb_delete(). */ - WARN_ON_ONCE(landlock_inode(inode)->object); + inode_sec = inode_security + landlock_blob_sizes.lbs_inode; + WARN_ON_ONCE(inode_sec->object); } /* Super-block hooks */ @@ -1637,7 +1640,7 @@ static int hook_file_ioctl_compat(struct file *file, unsigned int cmd, } static struct security_hook_list landlock_hooks[] __ro_after_init = { - LSM_HOOK_INIT(inode_free_security, hook_inode_free_security), + LSM_HOOK_INIT(inode_free_security_rcu, hook_inode_free_security_rcu), LSM_HOOK_INIT(sb_delete, hook_sb_delete), LSM_HOOK_INIT(sb_mount, hook_sb_mount), diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c index cd84d8ea1dfb..f2bdbd55aa2b 100644 --- a/security/lockdown/lockdown.c +++ b/security/lockdown/lockdown.c @@ -76,7 +76,7 @@ static struct security_hook_list lockdown_hooks[] __ro_after_init = { LSM_HOOK_INIT(locked_down, lockdown_is_locked_down), }; -const struct lsm_id lockdown_lsmid = { +static const struct lsm_id lockdown_lsmid = { .name = "lockdown", .id = LSM_ID_LOCKDOWN, }; diff --git a/security/security.c b/security/security.c index 8cee5b6c6e6d..4564a0a1e4ef 100644 --- a/security/security.c +++ b/security/security.c @@ -28,30 +28,29 @@ #include <linux/xattr.h> #include <linux/msg.h> #include <linux/overflow.h> +#include <linux/perf_event.h> +#include <linux/fs.h> #include <net/flow.h> +#include <net/sock.h> -/* How many LSMs were built into the kernel? */ -#define LSM_COUNT (__end_lsm_info - __start_lsm_info) +#define SECURITY_HOOK_ACTIVE_KEY(HOOK, IDX) security_hook_active_##HOOK##_##IDX /* - * How many LSMs are built into the kernel as determined at - * build time. Used to determine fixed array sizes. - * The capability module is accounted for by CONFIG_SECURITY - */ -#define LSM_CONFIG_COUNT ( \ - (IS_ENABLED(CONFIG_SECURITY) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_TOMOYO) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_YAMA) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_LOADPIN) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_IMA) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_EVM) ? 1 : 0)) + * Identifier for the LSM static calls. + * HOOK is an LSM hook as defined in linux/lsm_hookdefs.h + * IDX is the index of the static call. 0 <= NUM < MAX_LSM_COUNT + */ +#define LSM_STATIC_CALL(HOOK, IDX) lsm_static_call_##HOOK##_##IDX + +/* + * Call the macro M for each LSM hook MAX_LSM_COUNT times. + */ +#define LSM_LOOP_UNROLL(M, ...) \ +do { \ + UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__) \ +} while (0) + +#define LSM_DEFINE_UNROLL(M, ...) UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__) /* * These are descriptions of the reasons that can be passed to the @@ -92,7 +91,6 @@ const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX + 1] = { [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality", }; -struct security_hook_heads security_hook_heads __ro_after_init; static BLOCKING_NOTIFIER_HEAD(blocking_lsm_notifier_chain); static struct kmem_cache *lsm_file_cache; @@ -108,9 +106,58 @@ static __initdata const char *chosen_major_lsm; static __initconst const char *const builtin_lsm_order = CONFIG_LSM; /* Ordered list of LSMs to initialize. */ -static __initdata struct lsm_info **ordered_lsms; +static __initdata struct lsm_info *ordered_lsms[MAX_LSM_COUNT + 1]; static __initdata struct lsm_info *exclusive; +#ifdef CONFIG_HAVE_STATIC_CALL +#define LSM_HOOK_TRAMP(NAME, NUM) \ + &STATIC_CALL_TRAMP(LSM_STATIC_CALL(NAME, NUM)) +#else +#define LSM_HOOK_TRAMP(NAME, NUM) NULL +#endif + +/* + * Define static calls and static keys for each LSM hook. + */ +#define DEFINE_LSM_STATIC_CALL(NUM, NAME, RET, ...) \ + DEFINE_STATIC_CALL_NULL(LSM_STATIC_CALL(NAME, NUM), \ + *((RET(*)(__VA_ARGS__))NULL)); \ + DEFINE_STATIC_KEY_FALSE(SECURITY_HOOK_ACTIVE_KEY(NAME, NUM)); + +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + LSM_DEFINE_UNROLL(DEFINE_LSM_STATIC_CALL, NAME, RET, __VA_ARGS__) +#include <linux/lsm_hook_defs.h> +#undef LSM_HOOK +#undef DEFINE_LSM_STATIC_CALL + +/* + * Initialise a table of static calls for each LSM hook. + * DEFINE_STATIC_CALL_NULL invocation above generates a key (STATIC_CALL_KEY) + * and a trampoline (STATIC_CALL_TRAMP) which are used to call + * __static_call_update when updating the static call. + * + * The static calls table is used by early LSMs, some architectures can fault on + * unaligned accesses and the fault handling code may not be ready by then. + * Thus, the static calls table should be aligned to avoid any unhandled faults + * in early init. + */ +struct lsm_static_calls_table + static_calls_table __ro_after_init __aligned(sizeof(u64)) = { +#define INIT_LSM_STATIC_CALL(NUM, NAME) \ + (struct lsm_static_call) { \ + .key = &STATIC_CALL_KEY(LSM_STATIC_CALL(NAME, NUM)), \ + .trampoline = LSM_HOOK_TRAMP(NAME, NUM), \ + .active = &SECURITY_HOOK_ACTIVE_KEY(NAME, NUM), \ + }, +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + .NAME = { \ + LSM_DEFINE_UNROLL(INIT_LSM_STATIC_CALL, NAME) \ + }, +#include <linux/lsm_hook_defs.h> +#undef LSM_HOOK +#undef INIT_LSM_STATIC_CALL + }; + static __initdata bool debug; #define init_debug(...) \ do { \ @@ -171,7 +218,7 @@ static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from) if (exists_ordered_lsm(lsm)) return; - if (WARN(last_lsm == LSM_COUNT, "%s: out of LSM slots!?\n", from)) + if (WARN(last_lsm == MAX_LSM_COUNT, "%s: out of LSM static calls!?\n", from)) return; /* Enable this LSM, if it is not already set. */ @@ -218,6 +265,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) lsm_set_blob_size(&needed->lbs_cred, &blob_sizes.lbs_cred); lsm_set_blob_size(&needed->lbs_file, &blob_sizes.lbs_file); + lsm_set_blob_size(&needed->lbs_ib, &blob_sizes.lbs_ib); /* * The inode blob gets an rcu_head in addition to * what the modules might need. @@ -226,11 +274,16 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) blob_sizes.lbs_inode = sizeof(struct rcu_head); lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode); lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc); + lsm_set_blob_size(&needed->lbs_key, &blob_sizes.lbs_key); lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg); + lsm_set_blob_size(&needed->lbs_perf_event, &blob_sizes.lbs_perf_event); + lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock); lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock); lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task); + lsm_set_blob_size(&needed->lbs_tun_dev, &blob_sizes.lbs_tun_dev); lsm_set_blob_size(&needed->lbs_xattr_count, &blob_sizes.lbs_xattr_count); + lsm_set_blob_size(&needed->lbs_bdev, &blob_sizes.lbs_bdev); } /* Prepare LSM for initialization. */ @@ -268,7 +321,7 @@ static void __init initialize_lsm(struct lsm_info *lsm) * Current index to use while initializing the lsm id list. */ u32 lsm_active_cnt __ro_after_init; -const struct lsm_id *lsm_idlist[LSM_CONFIG_COUNT]; +const struct lsm_id *lsm_idlist[MAX_LSM_COUNT]; /* Populate ordered LSMs list from comma-separated LSM name list. */ static void __init ordered_lsm_parse(const char *order, const char *origin) @@ -350,6 +403,25 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) kfree(sep); } +static void __init lsm_static_call_init(struct security_hook_list *hl) +{ + struct lsm_static_call *scall = hl->scalls; + int i; + + for (i = 0; i < MAX_LSM_COUNT; i++) { + /* Update the first static call that is not used yet */ + if (!scall->hl) { + __static_call_update(scall->key, scall->trampoline, + hl->hook.lsm_func_addr); + scall->hl = hl; + static_branch_enable(scall->active); + return; + } + scall++; + } + panic("%s - Ran out of static slots.\n", __func__); +} + static void __init lsm_early_cred(struct cred *cred); static void __init lsm_early_task(struct task_struct *task); @@ -378,9 +450,6 @@ static void __init ordered_lsm_init(void) { struct lsm_info **lsm; - ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms), - GFP_KERNEL); - if (chosen_lsm_order) { if (chosen_major_lsm) { pr_warn("security=%s is ignored because it is superseded by lsm=%s\n", @@ -398,12 +467,20 @@ static void __init ordered_lsm_init(void) init_debug("cred blob size = %d\n", blob_sizes.lbs_cred); init_debug("file blob size = %d\n", blob_sizes.lbs_file); + init_debug("ib blob size = %d\n", blob_sizes.lbs_ib); init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); +#ifdef CONFIG_KEYS + init_debug("key blob size = %d\n", blob_sizes.lbs_key); +#endif /* CONFIG_KEYS */ init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); + init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); + init_debug("perf event blob size = %d\n", blob_sizes.lbs_perf_event); init_debug("task blob size = %d\n", blob_sizes.lbs_task); + init_debug("tun device blob size = %d\n", blob_sizes.lbs_tun_dev); init_debug("xattr slots = %d\n", blob_sizes.lbs_xattr_count); + init_debug("bdev blob size = %d\n", blob_sizes.lbs_bdev); /* * Create any kmem_caches needed for blobs @@ -421,19 +498,12 @@ static void __init ordered_lsm_init(void) lsm_early_task(current); for (lsm = ordered_lsms; *lsm; lsm++) initialize_lsm(*lsm); - - kfree(ordered_lsms); } int __init early_security_init(void) { struct lsm_info *lsm; -#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ - INIT_HLIST_HEAD(&security_hook_heads.NAME); -#include "linux/lsm_hook_defs.h" -#undef LSM_HOOK - for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) { if (!lsm->enabled) lsm->enabled = &lsm_enabled_true; @@ -554,14 +624,14 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, * Look at the previous entry, if there is one, for duplication. */ if (lsm_active_cnt == 0 || lsm_idlist[lsm_active_cnt - 1] != lsmid) { - if (lsm_active_cnt >= LSM_CONFIG_COUNT) + if (lsm_active_cnt >= MAX_LSM_COUNT) panic("%s Too many LSMs registered.\n", __func__); lsm_idlist[lsm_active_cnt++] = lsmid; } for (i = 0; i < count; i++) { hooks[i].lsmid = lsmid; - hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); + lsm_static_call_init(&hooks[i]); } /* @@ -596,28 +666,43 @@ int unregister_blocking_lsm_notifier(struct notifier_block *nb) EXPORT_SYMBOL(unregister_blocking_lsm_notifier); /** - * lsm_cred_alloc - allocate a composite cred blob - * @cred: the cred that needs a blob + * lsm_blob_alloc - allocate a composite blob + * @dest: the destination for the blob + * @size: the size of the blob * @gfp: allocation type * - * Allocate the cred blob for all the modules + * Allocate a blob for all the modules * * Returns 0, or -ENOMEM if memory can't be allocated. */ -static int lsm_cred_alloc(struct cred *cred, gfp_t gfp) +static int lsm_blob_alloc(void **dest, size_t size, gfp_t gfp) { - if (blob_sizes.lbs_cred == 0) { - cred->security = NULL; + if (size == 0) { + *dest = NULL; return 0; } - cred->security = kzalloc(blob_sizes.lbs_cred, gfp); - if (cred->security == NULL) + *dest = kzalloc(size, gfp); + if (*dest == NULL) return -ENOMEM; return 0; } /** + * lsm_cred_alloc - allocate a composite cred blob + * @cred: the cred that needs a blob + * @gfp: allocation type + * + * Allocate the cred blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_cred_alloc(struct cred *cred, gfp_t gfp) +{ + return lsm_blob_alloc(&cred->security, blob_sizes.lbs_cred, gfp); +} + +/** * lsm_early_cred - during initialization allocate a composite cred blob * @cred: the cred that needs a blob * @@ -660,7 +745,7 @@ static int lsm_file_alloc(struct file *file) * * Returns 0, or -ENOMEM if memory can't be allocated. */ -int lsm_inode_alloc(struct inode *inode) +static int lsm_inode_alloc(struct inode *inode) { if (!lsm_inode_cache) { inode->i_security = NULL; @@ -683,15 +768,7 @@ int lsm_inode_alloc(struct inode *inode) */ static int lsm_task_alloc(struct task_struct *task) { - if (blob_sizes.lbs_task == 0) { - task->security = NULL; - return 0; - } - - task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL); - if (task->security == NULL) - return -ENOMEM; - return 0; + return lsm_blob_alloc(&task->security, blob_sizes.lbs_task, GFP_KERNEL); } /** @@ -704,16 +781,23 @@ static int lsm_task_alloc(struct task_struct *task) */ static int lsm_ipc_alloc(struct kern_ipc_perm *kip) { - if (blob_sizes.lbs_ipc == 0) { - kip->security = NULL; - return 0; - } + return lsm_blob_alloc(&kip->security, blob_sizes.lbs_ipc, GFP_KERNEL); +} - kip->security = kzalloc(blob_sizes.lbs_ipc, GFP_KERNEL); - if (kip->security == NULL) - return -ENOMEM; - return 0; +#ifdef CONFIG_KEYS +/** + * lsm_key_alloc - allocate a composite key blob + * @key: the key that needs a blob + * + * Allocate the key blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_key_alloc(struct key *key) +{ + return lsm_blob_alloc(&key->security, blob_sizes.lbs_key, GFP_KERNEL); } +#endif /* CONFIG_KEYS */ /** * lsm_msg_msg_alloc - allocate a composite msg_msg blob @@ -725,14 +809,29 @@ static int lsm_ipc_alloc(struct kern_ipc_perm *kip) */ static int lsm_msg_msg_alloc(struct msg_msg *mp) { - if (blob_sizes.lbs_msg_msg == 0) { - mp->security = NULL; + return lsm_blob_alloc(&mp->security, blob_sizes.lbs_msg_msg, + GFP_KERNEL); +} + +/** + * lsm_bdev_alloc - allocate a composite block_device blob + * @bdev: the block_device that needs a blob + * + * Allocate the block_device blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_bdev_alloc(struct block_device *bdev) +{ + if (blob_sizes.lbs_bdev == 0) { + bdev->bd_security = NULL; return 0; } - mp->security = kzalloc(blob_sizes.lbs_msg_msg, GFP_KERNEL); - if (mp->security == NULL) + bdev->bd_security = kzalloc(blob_sizes.lbs_bdev, GFP_KERNEL); + if (!bdev->bd_security) return -ENOMEM; + return 0; } @@ -760,15 +859,8 @@ static void __init lsm_early_task(struct task_struct *task) */ static int lsm_superblock_alloc(struct super_block *sb) { - if (blob_sizes.lbs_superblock == 0) { - sb->s_security = NULL; - return 0; - } - - sb->s_security = kzalloc(blob_sizes.lbs_superblock, GFP_KERNEL); - if (sb->s_security == NULL) - return -ENOMEM; - return 0; + return lsm_blob_alloc(&sb->s_security, blob_sizes.lbs_superblock, + GFP_KERNEL); } /** @@ -853,29 +945,43 @@ out: * call_int_hook: * This is a hook that returns a value. */ +#define __CALL_STATIC_VOID(NUM, HOOK, ...) \ +do { \ + if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \ + static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \ + } \ +} while (0); -#define call_void_hook(FUNC, ...) \ - do { \ - struct security_hook_list *P; \ - \ - hlist_for_each_entry(P, &security_hook_heads.FUNC, list) \ - P->hook.FUNC(__VA_ARGS__); \ +#define call_void_hook(HOOK, ...) \ + do { \ + LSM_LOOP_UNROLL(__CALL_STATIC_VOID, HOOK, __VA_ARGS__); \ } while (0) -#define call_int_hook(FUNC, ...) ({ \ - int RC = LSM_RET_DEFAULT(FUNC); \ - do { \ - struct security_hook_list *P; \ - \ - hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \ - RC = P->hook.FUNC(__VA_ARGS__); \ - if (RC != LSM_RET_DEFAULT(FUNC)) \ - break; \ - } \ - } while (0); \ - RC; \ + +#define __CALL_STATIC_INT(NUM, R, HOOK, LABEL, ...) \ +do { \ + if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \ + R = static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \ + if (R != LSM_RET_DEFAULT(HOOK)) \ + goto LABEL; \ + } \ +} while (0); + +#define call_int_hook(HOOK, ...) \ +({ \ + __label__ OUT; \ + int RC = LSM_RET_DEFAULT(HOOK); \ + \ + LSM_LOOP_UNROLL(__CALL_STATIC_INT, RC, HOOK, OUT, __VA_ARGS__); \ +OUT: \ + RC; \ }) +#define lsm_for_each_hook(scall, NAME) \ + for (scall = static_calls_table.NAME; \ + scall - static_calls_table.NAME < MAX_LSM_COUNT; scall++) \ + if (static_key_enabled(&scall->active->key)) + /* Security operations */ /** @@ -1110,20 +1216,19 @@ int security_settime64(const struct timespec64 *ts, const struct timezone *tz) */ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) { - struct security_hook_list *hp; + struct lsm_static_call *scall; int cap_sys_admin = 1; int rc; /* - * The module will respond with a positive value if - * it thinks the __vm_enough_memory() call should be - * made with the cap_sys_admin set. If all of the modules - * agree that it should be set it will. If any module - * thinks it should not be set it won't. + * The module will respond with 0 if it thinks the __vm_enough_memory() + * call should be made with the cap_sys_admin set. If all of the modules + * agree that it should be set it will. If any module thinks it should + * not be set it won't. */ - hlist_for_each_entry(hp, &security_hook_heads.vm_enough_memory, list) { - rc = hp->hook.vm_enough_memory(mm, pages); - if (rc <= 0) { + lsm_for_each_hook(scall, vm_enough_memory) { + rc = scall->hl->hook.vm_enough_memory(mm, pages); + if (rc < 0) { cap_sys_admin = 0; break; } @@ -1269,13 +1374,12 @@ int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param) { - struct security_hook_list *hp; + struct lsm_static_call *scall; int trc; int rc = -ENOPARAM; - hlist_for_each_entry(hp, &security_hook_heads.fs_context_parse_param, - list) { - trc = hp->hook.fs_context_parse_param(fc, param); + lsm_for_each_hook(scall, fs_context_parse_param) { + trc = scall->hl->hook.fs_context_parse_param(fc, param); if (trc == 0) rc = 0; else if (trc != -ENOPARAM) @@ -1505,12 +1609,11 @@ int security_sb_set_mnt_opts(struct super_block *sb, unsigned long kern_flags, unsigned long *set_kern_flags) { - struct security_hook_list *hp; + struct lsm_static_call *scall; int rc = mnt_opts ? -EOPNOTSUPP : LSM_RET_DEFAULT(sb_set_mnt_opts); - hlist_for_each_entry(hp, &security_hook_heads.sb_set_mnt_opts, - list) { - rc = hp->hook.sb_set_mnt_opts(sb, mnt_opts, kern_flags, + lsm_for_each_hook(scall, sb_set_mnt_opts) { + rc = scall->hl->hook.sb_set_mnt_opts(sb, mnt_opts, kern_flags, set_kern_flags); if (rc != LSM_RET_DEFAULT(sb_set_mnt_opts)) break; @@ -1596,9 +1699,8 @@ int security_inode_alloc(struct inode *inode) static void inode_free_by_rcu(struct rcu_head *head) { - /* - * The rcu head is at the start of the inode blob - */ + /* The rcu head is at the start of the inode blob */ + call_void_hook(inode_free_security_rcu, head); kmem_cache_free(lsm_inode_cache, head); } @@ -1606,23 +1708,24 @@ static void inode_free_by_rcu(struct rcu_head *head) * security_inode_free() - Free an inode's LSM blob * @inode: the inode * - * Deallocate the inode security structure and set @inode->i_security to NULL. + * Release any LSM resources associated with @inode, although due to the + * inode's RCU protections it is possible that the resources will not be + * fully released until after the current RCU grace period has elapsed. + * + * It is important for LSMs to note that despite being present in a call to + * security_inode_free(), @inode may still be referenced in a VFS path walk + * and calls to security_inode_permission() may be made during, or after, + * a call to security_inode_free(). For this reason the inode->i_security + * field is released via a call_rcu() callback and any LSMs which need to + * retain inode state for use in security_inode_permission() should only + * release that state in the inode_free_security_rcu() LSM hook callback. */ void security_inode_free(struct inode *inode) { call_void_hook(inode_free_security, inode); - /* - * The inode may still be referenced in a path walk and - * a call to security_inode_permission() can be made - * after inode_free_security() is called. Ideally, the VFS - * wouldn't do this, but fixing that is a much harder - * job. For now, simply free the i_security via RCU, and - * leave the current inode->i_security pointer intact. - * The inode will be freed after the RCU grace period too. - */ - if (inode->i_security) - call_rcu((struct rcu_head *)inode->i_security, - inode_free_by_rcu); + if (!inode->i_security) + return; + call_rcu((struct rcu_head *)inode->i_security, inode_free_by_rcu); } /** @@ -1705,7 +1808,7 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, const initxattrs initxattrs, void *fs_data) { - struct security_hook_list *hp; + struct lsm_static_call *scall; struct xattr *new_xattrs = NULL; int ret = -EOPNOTSUPP, xattr_count = 0; @@ -1723,9 +1826,8 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, return -ENOMEM; } - hlist_for_each_entry(hp, &security_hook_heads.inode_init_security, - list) { - ret = hp->hook.inode_init_security(inode, dir, qstr, new_xattrs, + lsm_for_each_hook(scall, inode_init_security) { + ret = scall->hl->hook.inode_init_security(inode, dir, qstr, new_xattrs, &xattr_count); if (ret && ret != -EOPNOTSUPP) goto out; @@ -2661,19 +2763,14 @@ EXPORT_SYMBOL(security_inode_copy_up); * lower layer to the union/overlay layer. The caller is responsible for * reading and writing the xattrs, this hook is merely a filter. * - * Return: Returns 0 to accept the xattr, 1 to discard the xattr, -EOPNOTSUPP - * if the security module does not know about attribute, or a negative - * error code to abort the copy up. + * Return: Returns 0 to accept the xattr, -ECANCELED to discard the xattr, + * -EOPNOTSUPP if the security module does not know about attribute, + * or a negative error code to abort the copy up. */ int security_inode_copy_up_xattr(struct dentry *src, const char *name) { int rc; - /* - * The implementation can return 0 (accept the xattr), 1 (discard the - * xattr), -EOPNOTSUPP if it does not know anything about the xattr or - * any other error code in case of an error. - */ rc = call_int_hook(inode_copy_up_xattr, src, name); if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) return rc; @@ -2683,6 +2780,26 @@ int security_inode_copy_up_xattr(struct dentry *src, const char *name) EXPORT_SYMBOL(security_inode_copy_up_xattr); /** + * security_inode_setintegrity() - Set the inode's integrity data + * @inode: inode + * @type: type of integrity, e.g. hash digest, signature, etc + * @value: the integrity value + * @size: size of the integrity value + * + * Register a verified integrity measurement of a inode with LSMs. + * LSMs should free the previously saved data if @value is NULL. + * + * Return: Returns 0 on success, negative values on failure. + */ +int security_inode_setintegrity(const struct inode *inode, + enum lsm_integrity_type type, const void *value, + size_t size) +{ + return call_int_hook(inode_setintegrity, inode, type, value, size); +} +EXPORT_SYMBOL(security_inode_setintegrity); + +/** * security_kernfs_init_security() - Init LSM context for a kernfs node * @kn_dir: parent kernfs node * @kn: the kernfs node to initialize @@ -2931,6 +3048,8 @@ int security_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg) * Save owner security information (typically from current->security) in * file->f_security for later use by the send_sigiotask hook. * + * This hook is called with file->f_owner.lock held. + * * Return: Returns 0 on success. */ void security_file_set_fowner(struct file *file) @@ -3557,10 +3676,10 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, { int thisrc; int rc = LSM_RET_DEFAULT(task_prctl); - struct security_hook_list *hp; + struct lsm_static_call *scall; - hlist_for_each_entry(hp, &security_hook_heads.task_prctl, list) { - thisrc = hp->hook.task_prctl(option, arg2, arg3, arg4, arg5); + lsm_for_each_hook(scall, task_prctl) { + thisrc = scall->hl->hook.task_prctl(option, arg2, arg3, arg4, arg5); if (thisrc != LSM_RET_DEFAULT(task_prctl)) { rc = thisrc; if (thisrc != 0) @@ -3966,7 +4085,7 @@ EXPORT_SYMBOL(security_d_instantiate); int security_getselfattr(unsigned int attr, struct lsm_ctx __user *uctx, u32 __user *size, u32 flags) { - struct security_hook_list *hp; + struct lsm_static_call *scall; struct lsm_ctx lctx = { .id = LSM_ID_UNDEF, }; u8 __user *base = (u8 __user *)uctx; u32 entrysize; @@ -4004,13 +4123,13 @@ int security_getselfattr(unsigned int attr, struct lsm_ctx __user *uctx, * In the usual case gather all the data from the LSMs. * In the single case only get the data from the LSM specified. */ - hlist_for_each_entry(hp, &security_hook_heads.getselfattr, list) { - if (single && lctx.id != hp->lsmid->id) + lsm_for_each_hook(scall, getselfattr) { + if (single && lctx.id != scall->hl->lsmid->id) continue; entrysize = left; if (base) uctx = (struct lsm_ctx __user *)(base + total); - rc = hp->hook.getselfattr(attr, uctx, &entrysize, flags); + rc = scall->hl->hook.getselfattr(attr, uctx, &entrysize, flags); if (rc == -EOPNOTSUPP) { rc = 0; continue; @@ -4059,7 +4178,7 @@ int security_getselfattr(unsigned int attr, struct lsm_ctx __user *uctx, int security_setselfattr(unsigned int attr, struct lsm_ctx __user *uctx, u32 size, u32 flags) { - struct security_hook_list *hp; + struct lsm_static_call *scall; struct lsm_ctx *lctx; int rc = LSM_RET_DEFAULT(setselfattr); u64 required_len; @@ -4082,9 +4201,9 @@ int security_setselfattr(unsigned int attr, struct lsm_ctx __user *uctx, goto free_out; } - hlist_for_each_entry(hp, &security_hook_heads.setselfattr, list) - if ((hp->lsmid->id) == lctx->id) { - rc = hp->hook.setselfattr(attr, lctx, size, flags); + lsm_for_each_hook(scall, setselfattr) + if ((scall->hl->lsmid->id) == lctx->id) { + rc = scall->hl->hook.setselfattr(attr, lctx, size, flags); break; } @@ -4107,12 +4226,12 @@ free_out: int security_getprocattr(struct task_struct *p, int lsmid, const char *name, char **value) { - struct security_hook_list *hp; + struct lsm_static_call *scall; - hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { - if (lsmid != 0 && lsmid != hp->lsmid->id) + lsm_for_each_hook(scall, getprocattr) { + if (lsmid != 0 && lsmid != scall->hl->lsmid->id) continue; - return hp->hook.getprocattr(p, name, value); + return scall->hl->hook.getprocattr(p, name, value); } return LSM_RET_DEFAULT(getprocattr); } @@ -4131,12 +4250,12 @@ int security_getprocattr(struct task_struct *p, int lsmid, const char *name, */ int security_setprocattr(int lsmid, const char *name, void *value, size_t size) { - struct security_hook_list *hp; + struct lsm_static_call *scall; - hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { - if (lsmid != 0 && lsmid != hp->lsmid->id) + lsm_for_each_hook(scall, setprocattr) { + if (lsmid != 0 && lsmid != scall->hl->lsmid->id) continue; - return hp->hook.setprocattr(name, value, size); + return scall->hl->hook.setprocattr(name, value, size); } return LSM_RET_DEFAULT(setprocattr); } @@ -4674,6 +4793,20 @@ int security_socket_getpeersec_dgram(struct socket *sock, EXPORT_SYMBOL(security_socket_getpeersec_dgram); /** + * lsm_sock_alloc - allocate a composite sock blob + * @sock: the sock that needs a blob + * @gfp: allocation mode + * + * Allocate the sock blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_sock_alloc(struct sock *sock, gfp_t gfp) +{ + return lsm_blob_alloc(&sock->sk_security, blob_sizes.lbs_sock, gfp); +} + +/** * security_sk_alloc() - Allocate and initialize a sock's LSM blob * @sk: sock * @family: protocol family @@ -4686,7 +4819,14 @@ EXPORT_SYMBOL(security_socket_getpeersec_dgram); */ int security_sk_alloc(struct sock *sk, int family, gfp_t priority) { - return call_int_hook(sk_alloc_security, sk, family, priority); + int rc = lsm_sock_alloc(sk, priority); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(sk_alloc_security, sk, family, priority); + if (unlikely(rc)) + security_sk_free(sk); + return rc; } /** @@ -4698,6 +4838,8 @@ int security_sk_alloc(struct sock *sk, int family, gfp_t priority) void security_sk_free(struct sock *sk) { call_void_hook(sk_free_security, sk); + kfree(sk->sk_security); + sk->sk_security = NULL; } /** @@ -4845,7 +4987,18 @@ EXPORT_SYMBOL(security_secmark_refcount_dec); */ int security_tun_dev_alloc_security(void **security) { - return call_int_hook(tun_dev_alloc_security, security); + int rc; + + rc = lsm_blob_alloc(security, blob_sizes.lbs_tun_dev, GFP_KERNEL); + if (rc) + return rc; + + rc = call_int_hook(tun_dev_alloc_security, *security); + if (rc) { + kfree(*security); + *security = NULL; + } + return rc; } EXPORT_SYMBOL(security_tun_dev_alloc_security); @@ -4857,7 +5010,7 @@ EXPORT_SYMBOL(security_tun_dev_alloc_security); */ void security_tun_dev_free_security(void *security) { - call_void_hook(tun_dev_free_security, security); + kfree(security); } EXPORT_SYMBOL(security_tun_dev_free_security); @@ -5053,7 +5206,18 @@ EXPORT_SYMBOL(security_ib_endport_manage_subnet); */ int security_ib_alloc_security(void **sec) { - return call_int_hook(ib_alloc_security, sec); + int rc; + + rc = lsm_blob_alloc(sec, blob_sizes.lbs_ib, GFP_KERNEL); + if (rc) + return rc; + + rc = call_int_hook(ib_alloc_security, *sec); + if (rc) { + kfree(*sec); + *sec = NULL; + } + return rc; } EXPORT_SYMBOL(security_ib_alloc_security); @@ -5065,7 +5229,7 @@ EXPORT_SYMBOL(security_ib_alloc_security); */ void security_ib_free_security(void *sec) { - call_void_hook(ib_free_security, sec); + kfree(sec); } EXPORT_SYMBOL(security_ib_free_security); #endif /* CONFIG_SECURITY_INFINIBAND */ @@ -5223,7 +5387,7 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *xp, const struct flowi_common *flic) { - struct security_hook_list *hp; + struct lsm_static_call *scall; int rc = LSM_RET_DEFAULT(xfrm_state_pol_flow_match); /* @@ -5235,9 +5399,8 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, * For speed optimization, we explicitly break the loop rather than * using the macro */ - hlist_for_each_entry(hp, &security_hook_heads.xfrm_state_pol_flow_match, - list) { - rc = hp->hook.xfrm_state_pol_flow_match(x, xp, flic); + lsm_for_each_hook(scall, xfrm_state_pol_flow_match) { + rc = scall->hl->hook.xfrm_state_pol_flow_match(x, xp, flic); break; } return rc; @@ -5282,7 +5445,14 @@ EXPORT_SYMBOL(security_skb_classify_flow); int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { - return call_int_hook(key_alloc, key, cred, flags); + int rc = lsm_key_alloc(key); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(key_alloc, key, cred, flags); + if (unlikely(rc)) + security_key_free(key); + return rc; } /** @@ -5293,7 +5463,8 @@ int security_key_alloc(struct key *key, const struct cred *cred, */ void security_key_free(struct key *key) { - call_void_hook(key_free, key); + kfree(key->security); + key->security = NULL; } /** @@ -5596,6 +5767,85 @@ int security_locked_down(enum lockdown_reason what) } EXPORT_SYMBOL(security_locked_down); +/** + * security_bdev_alloc() - Allocate a block device LSM blob + * @bdev: block device + * + * Allocate and attach a security structure to @bdev->bd_security. The + * security field is initialized to NULL when the bdev structure is + * allocated. + * + * Return: Return 0 if operation was successful. + */ +int security_bdev_alloc(struct block_device *bdev) +{ + int rc = 0; + + rc = lsm_bdev_alloc(bdev); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bdev_alloc_security, bdev); + if (unlikely(rc)) + security_bdev_free(bdev); + + return rc; +} +EXPORT_SYMBOL(security_bdev_alloc); + +/** + * security_bdev_free() - Free a block device's LSM blob + * @bdev: block device + * + * Deallocate the bdev security structure and set @bdev->bd_security to NULL. + */ +void security_bdev_free(struct block_device *bdev) +{ + if (!bdev->bd_security) + return; + + call_void_hook(bdev_free_security, bdev); + + kfree(bdev->bd_security); + bdev->bd_security = NULL; +} +EXPORT_SYMBOL(security_bdev_free); + +/** + * security_bdev_setintegrity() - Set the device's integrity data + * @bdev: block device + * @type: type of integrity, e.g. hash digest, signature, etc + * @value: the integrity value + * @size: size of the integrity value + * + * Register a verified integrity measurement of a bdev with LSMs. + * LSMs should free the previously saved data if @value is NULL. + * Please note that the new hook should be invoked every time the security + * information is updated to keep these data current. For example, in dm-verity, + * if the mapping table is reloaded and configured to use a different dm-verity + * target with a new roothash and signing information, the previously stored + * data in the LSM blob will become obsolete. It is crucial to re-invoke the + * hook to refresh these data and ensure they are up to date. This necessity + * arises from the design of device-mapper, where a device-mapper device is + * first created, and then targets are subsequently loaded into it. These + * targets can be modified multiple times during the device's lifetime. + * Therefore, while the LSM blob is allocated during the creation of the block + * device, its actual contents are not initialized at this stage and can change + * substantially over time. This includes alterations from data that the LSMs + * 'trusts' to those they do not, making it essential to handle these changes + * correctly. Failure to address this dynamic aspect could potentially allow + * for bypassing LSM checks. + * + * Return: Returns 0 on success, negative values on failure. + */ +int security_bdev_setintegrity(struct block_device *bdev, + enum lsm_integrity_type type, const void *value, + size_t size) +{ + return call_int_hook(bdev_setintegrity, bdev, type, value, size); +} +EXPORT_SYMBOL(security_bdev_setintegrity); + #ifdef CONFIG_PERF_EVENTS /** * security_perf_event_open() - Check if a perf event open is allowed @@ -5621,7 +5871,19 @@ int security_perf_event_open(struct perf_event_attr *attr, int type) */ int security_perf_event_alloc(struct perf_event *event) { - return call_int_hook(perf_event_alloc, event); + int rc; + + rc = lsm_blob_alloc(&event->security, blob_sizes.lbs_perf_event, + GFP_KERNEL); + if (rc) + return rc; + + rc = call_int_hook(perf_event_alloc, event); + if (rc) { + kfree(event->security); + event->security = NULL; + } + return rc; } /** @@ -5632,7 +5894,8 @@ int security_perf_event_alloc(struct perf_event *event) */ void security_perf_event_free(struct perf_event *event) { - call_void_hook(perf_event_free, event); + kfree(event->security); + event->security = NULL; } /** @@ -5703,3 +5966,13 @@ int security_uring_cmd(struct io_uring_cmd *ioucmd) return call_int_hook(uring_cmd, ioucmd); } #endif /* CONFIG_IO_URING */ + +/** + * security_initramfs_populated() - Notify LSMs that initramfs has been loaded + * + * Tells the LSMs the initramfs has been unpacked into the rootfs. + */ +void security_initramfs_populated(void) +{ + call_void_hook(initramfs_populated); +} diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index e9b630de2f79..bd3293021488 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2207,23 +2207,16 @@ static int selinux_syslog(int type) } /* - * Check that a process has enough memory to allocate a new virtual - * mapping. 0 means there is enough memory for the allocation to - * succeed and -ENOMEM implies there is not. + * Check permission for allocating a new virtual mapping. Returns + * 0 if permission is granted, negative error code if not. * * Do not audit the selinux permission check, as this is applied to all * processes that allocate mappings. */ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) { - int rc, cap_sys_admin = 0; - - rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, - CAP_OPT_NOAUDIT, true); - if (rc == 0) - cap_sys_admin = 1; - - return cap_sys_admin; + return cred_has_capability(current_cred(), CAP_SYS_ADMIN, + CAP_OPT_NOAUDIT, true); } /* binprm security operations */ @@ -3543,8 +3536,8 @@ static int selinux_inode_copy_up_xattr(struct dentry *dentry, const char *name) * xattrs up. Instead, filter out SELinux-related xattrs following * policy load. */ - if (selinux_initialized() && strcmp(name, XATTR_NAME_SELINUX) == 0) - return 1; /* Discard */ + if (selinux_initialized() && !strcmp(name, XATTR_NAME_SELINUX)) + return -ECANCELED; /* Discard */ /* * Any other attribute apart from SELINUX is not claimed, supported * by selinux. @@ -4599,7 +4592,7 @@ static int socket_sockcreate_sid(const struct task_security_struct *tsec, static int sock_has_perm(struct sock *sk, u32 perms) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct common_audit_data ad; struct lsm_network_audit net; @@ -4667,7 +4660,7 @@ static int selinux_socket_post_create(struct socket *sock, int family, isec->initialized = LABEL_INITIALIZED; if (sock->sk) { - sksec = sock->sk->sk_security; + sksec = selinux_sock(sock->sk); sksec->sclass = sclass; sksec->sid = sid; /* Allows detection of the first association on this socket */ @@ -4683,8 +4676,8 @@ static int selinux_socket_post_create(struct socket *sock, int family, static int selinux_socket_socketpair(struct socket *socka, struct socket *sockb) { - struct sk_security_struct *sksec_a = socka->sk->sk_security; - struct sk_security_struct *sksec_b = sockb->sk->sk_security; + struct sk_security_struct *sksec_a = selinux_sock(socka->sk); + struct sk_security_struct *sksec_b = selinux_sock(sockb->sk); sksec_a->peer_sid = sksec_b->sid; sksec_b->peer_sid = sksec_a->sid; @@ -4699,7 +4692,7 @@ static int selinux_socket_socketpair(struct socket *socka, static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) { struct sock *sk = sock->sk; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u16 family; int err; @@ -4839,7 +4832,7 @@ static int selinux_socket_connect_helper(struct socket *sock, struct sockaddr *address, int addrlen) { struct sock *sk = sock->sk; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); int err; err = sock_has_perm(sk, SOCKET__CONNECT); @@ -5017,9 +5010,9 @@ static int selinux_socket_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk) { - struct sk_security_struct *sksec_sock = sock->sk_security; - struct sk_security_struct *sksec_other = other->sk_security; - struct sk_security_struct *sksec_new = newsk->sk_security; + struct sk_security_struct *sksec_sock = selinux_sock(sock); + struct sk_security_struct *sksec_other = selinux_sock(other); + struct sk_security_struct *sksec_new = selinux_sock(newsk); struct common_audit_data ad; struct lsm_network_audit net; int err; @@ -5048,8 +5041,8 @@ static int selinux_socket_unix_stream_connect(struct sock *sock, static int selinux_socket_unix_may_send(struct socket *sock, struct socket *other) { - struct sk_security_struct *ssec = sock->sk->sk_security; - struct sk_security_struct *osec = other->sk->sk_security; + struct sk_security_struct *ssec = selinux_sock(sock->sk); + struct sk_security_struct *osec = selinux_sock(other->sk); struct common_audit_data ad; struct lsm_network_audit net; @@ -5086,7 +5079,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, u16 family) { int err = 0; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u32 sk_sid = sksec->sid; struct common_audit_data ad; struct lsm_network_audit net; @@ -5115,7 +5108,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { int err, peerlbl_active, secmark_active; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u16 family = sk->sk_family; u32 sk_sid = sksec->sid; struct common_audit_data ad; @@ -5183,7 +5176,7 @@ static int selinux_socket_getpeersec_stream(struct socket *sock, int err = 0; char *scontext = NULL; u32 scontext_len; - struct sk_security_struct *sksec = sock->sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sock->sk); u32 peer_sid = SECSID_NULL; if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || @@ -5243,34 +5236,27 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) { - struct sk_security_struct *sksec; - - sksec = kzalloc(sizeof(*sksec), priority); - if (!sksec) - return -ENOMEM; + struct sk_security_struct *sksec = selinux_sock(sk); sksec->peer_sid = SECINITSID_UNLABELED; sksec->sid = SECINITSID_UNLABELED; sksec->sclass = SECCLASS_SOCKET; selinux_netlbl_sk_security_reset(sksec); - sk->sk_security = sksec; return 0; } static void selinux_sk_free_security(struct sock *sk) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); - sk->sk_security = NULL; selinux_netlbl_sk_security_free(sksec); - kfree(sksec); } static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) { - struct sk_security_struct *sksec = sk->sk_security; - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); newsksec->sid = sksec->sid; newsksec->peer_sid = sksec->peer_sid; @@ -5284,7 +5270,7 @@ static void selinux_sk_getsecid(const struct sock *sk, u32 *secid) if (!sk) *secid = SECINITSID_ANY_SOCKET; else { - const struct sk_security_struct *sksec = sk->sk_security; + const struct sk_security_struct *sksec = selinux_sock(sk); *secid = sksec->sid; } @@ -5294,7 +5280,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent) { struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(parent)); - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || sk->sk_family == PF_UNIX) @@ -5311,7 +5297,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc, { struct sock *sk = asoc->base.sk; u16 family = sk->sk_family; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct common_audit_data ad; struct lsm_network_audit net; int err; @@ -5366,7 +5352,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc, static int selinux_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { - struct sk_security_struct *sksec = asoc->base.sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); u32 conn_sid; int err; @@ -5399,7 +5385,7 @@ static int selinux_sctp_assoc_request(struct sctp_association *asoc, static int selinux_sctp_assoc_established(struct sctp_association *asoc, struct sk_buff *skb) { - struct sk_security_struct *sksec = asoc->base.sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); if (!selinux_policycap_extsockclass()) return 0; @@ -5498,8 +5484,8 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname, static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk) { - struct sk_security_struct *sksec = sk->sk_security; - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); /* If policy does not support SECCLASS_SCTP_SOCKET then call * the non-sctp clone version. @@ -5515,8 +5501,8 @@ static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk) { - struct sk_security_struct *ssksec = ssk->sk_security; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *ssksec = selinux_sock(ssk); + struct sk_security_struct *sksec = selinux_sock(sk); ssksec->sclass = sksec->sclass; ssksec->sid = sksec->sid; @@ -5531,7 +5517,7 @@ static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk) static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); int err; u16 family = req->rsk_ops->family; u32 connsid; @@ -5552,7 +5538,7 @@ static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb, static void selinux_inet_csk_clone(struct sock *newsk, const struct request_sock *req) { - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *newsksec = selinux_sock(newsk); newsksec->sid = req->secid; newsksec->peer_sid = req->peer_secid; @@ -5569,7 +5555,7 @@ static void selinux_inet_csk_clone(struct sock *newsk, static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) { u16 family = sk->sk_family; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); /* handle mapped IPv4 packets arriving via IPv6 sockets */ if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) @@ -5600,24 +5586,14 @@ static void selinux_req_classify_flow(const struct request_sock *req, flic->flowic_secid = req->secid; } -static int selinux_tun_dev_alloc_security(void **security) +static int selinux_tun_dev_alloc_security(void *security) { - struct tun_security_struct *tunsec; + struct tun_security_struct *tunsec = selinux_tun_dev(security); - tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL); - if (!tunsec) - return -ENOMEM; tunsec->sid = current_sid(); - - *security = tunsec; return 0; } -static void selinux_tun_dev_free_security(void *security) -{ - kfree(security); -} - static int selinux_tun_dev_create(void) { u32 sid = current_sid(); @@ -5635,7 +5611,7 @@ static int selinux_tun_dev_create(void) static int selinux_tun_dev_attach_queue(void *security) { - struct tun_security_struct *tunsec = security; + struct tun_security_struct *tunsec = selinux_tun_dev(security); return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__ATTACH_QUEUE, NULL); @@ -5643,8 +5619,8 @@ static int selinux_tun_dev_attach_queue(void *security) static int selinux_tun_dev_attach(struct sock *sk, void *security) { - struct tun_security_struct *tunsec = security; - struct sk_security_struct *sksec = sk->sk_security; + struct tun_security_struct *tunsec = selinux_tun_dev(security); + struct sk_security_struct *sksec = selinux_sock(sk); /* we don't currently perform any NetLabel based labeling here and it * isn't clear that we would want to do so anyway; while we could apply @@ -5661,7 +5637,7 @@ static int selinux_tun_dev_attach(struct sock *sk, void *security) static int selinux_tun_dev_open(void *security) { - struct tun_security_struct *tunsec = security; + struct tun_security_struct *tunsec = selinux_tun_dev(security); u32 sid = current_sid(); int err; @@ -5767,7 +5743,7 @@ static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb, return NF_ACCEPT; /* standard practice, label using the parent socket */ - sksec = sk->sk_security; + sksec = selinux_sock(sk); sid = sksec->sid; } else sid = SECINITSID_KERNEL; @@ -5790,7 +5766,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, sk = skb_to_full_sk(skb); if (sk == NULL) return NF_ACCEPT; - sksec = sk->sk_security; + sksec = selinux_sock(sk); ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf); if (selinux_parse_skb(skb, &ad, NULL, 0, &proto)) @@ -5879,7 +5855,7 @@ static unsigned int selinux_ip_postroute(void *priv, u32 skb_sid; struct sk_security_struct *sksec; - sksec = sk->sk_security; + sksec = selinux_sock(sk); if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) return NF_DROP; /* At this point, if the returned skb peerlbl is SECSID_NULL @@ -5908,7 +5884,7 @@ static unsigned int selinux_ip_postroute(void *priv, } else { /* Locally generated packet, fetch the security label from the * associated socket. */ - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); peer_sid = sksec->sid; secmark_perm = PACKET__SEND; } @@ -5951,7 +5927,7 @@ static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) unsigned int data_len = skb->len; unsigned char *data = skb->data; struct nlmsghdr *nlh; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u16 sclass = sksec->sclass; u32 perm; @@ -6685,11 +6661,7 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred, unsigned long flags) { const struct task_security_struct *tsec; - struct key_security_struct *ksec; - - ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); - if (!ksec) - return -ENOMEM; + struct key_security_struct *ksec = selinux_key(k); tsec = selinux_cred(cred); if (tsec->keycreate_sid) @@ -6697,18 +6669,9 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred, else ksec->sid = tsec->sid; - k->security = ksec; return 0; } -static void selinux_key_free(struct key *k) -{ - struct key_security_struct *ksec = k->security; - - k->security = NULL; - kfree(ksec); -} - static int selinux_key_permission(key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm) @@ -6749,14 +6712,14 @@ static int selinux_key_permission(key_ref_t key_ref, sid = cred_sid(cred); key = key_ref_to_ptr(key_ref); - ksec = key->security; + ksec = selinux_key(key); return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL); } static int selinux_key_getsecurity(struct key *key, char **_buffer) { - struct key_security_struct *ksec = key->security; + struct key_security_struct *ksec = selinux_key(key); char *context = NULL; unsigned len; int rc; @@ -6826,23 +6789,13 @@ static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name, INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad); } -static int selinux_ib_alloc_security(void **ib_sec) +static int selinux_ib_alloc_security(void *ib_sec) { - struct ib_security_struct *sec; + struct ib_security_struct *sec = selinux_ib(ib_sec); - sec = kzalloc(sizeof(*sec), GFP_KERNEL); - if (!sec) - return -ENOMEM; sec->sid = current_sid(); - - *ib_sec = sec; return 0; } - -static void selinux_ib_free_security(void *ib_sec) -{ - kfree(ib_sec); -} #endif #ifdef CONFIG_BPF_SYSCALL @@ -7008,9 +6961,16 @@ struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = { .lbs_file = sizeof(struct file_security_struct), .lbs_inode = sizeof(struct inode_security_struct), .lbs_ipc = sizeof(struct ipc_security_struct), + .lbs_key = sizeof(struct key_security_struct), .lbs_msg_msg = sizeof(struct msg_security_struct), +#ifdef CONFIG_PERF_EVENTS + .lbs_perf_event = sizeof(struct perf_event_security_struct), +#endif + .lbs_sock = sizeof(struct sk_security_struct), .lbs_superblock = sizeof(struct superblock_security_struct), .lbs_xattr_count = SELINUX_INODE_INIT_XATTRS, + .lbs_tun_dev = sizeof(struct tun_security_struct), + .lbs_ib = sizeof(struct ib_security_struct), }; #ifdef CONFIG_PERF_EVENTS @@ -7037,24 +6997,12 @@ static int selinux_perf_event_alloc(struct perf_event *event) { struct perf_event_security_struct *perfsec; - perfsec = kzalloc(sizeof(*perfsec), GFP_KERNEL); - if (!perfsec) - return -ENOMEM; - + perfsec = selinux_perf_event(event->security); perfsec->sid = current_sid(); - event->security = perfsec; return 0; } -static void selinux_perf_event_free(struct perf_event *event) -{ - struct perf_event_security_struct *perfsec = event->security; - - event->security = NULL; - kfree(perfsec); -} - static int selinux_perf_event_read(struct perf_event *event) { struct perf_event_security_struct *perfsec = event->security; @@ -7322,7 +7270,6 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc), LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec), LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow), - LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security), LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create), LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue), LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach), @@ -7331,7 +7278,6 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access), LSM_HOOK_INIT(ib_endport_manage_subnet, selinux_ib_endport_manage_subnet), - LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security), #endif #ifdef CONFIG_SECURITY_NETWORK_XFRM LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free), @@ -7345,7 +7291,6 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { #endif #ifdef CONFIG_KEYS - LSM_HOOK_INIT(key_free, selinux_key_free), LSM_HOOK_INIT(key_permission, selinux_key_permission), LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity), #ifdef CONFIG_KEY_NOTIFICATIONS @@ -7370,7 +7315,6 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { #ifdef CONFIG_PERF_EVENTS LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open), - LSM_HOOK_INIT(perf_event_free, selinux_perf_event_free), LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read), LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write), #endif diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index dea1d6f3ed2d..c88cae81ee4c 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -195,4 +195,32 @@ selinux_superblock(const struct super_block *superblock) return superblock->s_security + selinux_blob_sizes.lbs_superblock; } +#ifdef CONFIG_KEYS +static inline struct key_security_struct *selinux_key(const struct key *key) +{ + return key->security + selinux_blob_sizes.lbs_key; +} +#endif /* CONFIG_KEYS */ + +static inline struct sk_security_struct *selinux_sock(const struct sock *sock) +{ + return sock->sk_security + selinux_blob_sizes.lbs_sock; +} + +static inline struct tun_security_struct *selinux_tun_dev(void *security) +{ + return security + selinux_blob_sizes.lbs_tun_dev; +} + +static inline struct ib_security_struct *selinux_ib(void *ib_sec) +{ + return ib_sec + selinux_blob_sizes.lbs_ib; +} + +static inline struct perf_event_security_struct * +selinux_perf_event(void *perf_event) +{ + return perf_event + selinux_blob_sizes.lbs_perf_event; +} + #endif /* _SELINUX_OBJSEC_H_ */ diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 5ad2fd68abbf..d51dfe892312 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -17,6 +17,7 @@ #include <linux/gfp.h> #include <linux/ip.h> #include <linux/ipv6.h> +#include <linux/lsm_hooks.h> #include <net/sock.h> #include <net/netlabel.h> #include <net/ip.h> @@ -68,7 +69,7 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) { int rc; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr; if (sksec->nlbl_secattr != NULL) @@ -101,7 +102,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr( const struct sock *sk, u32 sid) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr; if (secattr == NULL) @@ -241,7 +242,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, * being labeled by it's parent socket, if it is just exit */ sk = skb_to_full_sk(skb); if (sk != NULL) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (sksec->nlbl_state != NLBL_REQSKB) return 0; @@ -278,7 +279,7 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, { int rc; struct netlbl_lsm_secattr secattr; - struct sk_security_struct *sksec = asoc->base.sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); struct sockaddr_in addr4; struct sockaddr_in6 addr6; @@ -357,7 +358,7 @@ inet_conn_request_return: */ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (family == PF_INET || family == PF_INET6) sksec->nlbl_state = NLBL_LABELED; @@ -375,8 +376,8 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) */ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk) { - struct sk_security_struct *sksec = sk->sk_security; - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); newsksec->nlbl_state = sksec->nlbl_state; } @@ -394,7 +395,7 @@ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk) int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) { int rc; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr; if (family != PF_INET && family != PF_INET6) @@ -511,7 +512,7 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock, { int rc = 0; struct sock *sk = sock->sk; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr secattr; if (selinux_netlbl_option(level, optname) && @@ -549,7 +550,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk, struct sockaddr *addr) { int rc; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr; /* connected sockets are allowed to disconnect when the address family @@ -587,7 +588,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk, int selinux_netlbl_socket_connect_locked(struct sock *sk, struct sockaddr *addr) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (sksec->nlbl_state != NLBL_REQSKB && sksec->nlbl_state != NLBL_CONNLABELED) diff --git a/security/smack/smack.h b/security/smack/smack.h index 041688e5a77a..dbf8d7226eb5 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -355,6 +355,18 @@ static inline struct superblock_smack *smack_superblock( return superblock->s_security + smack_blob_sizes.lbs_superblock; } +static inline struct socket_smack *smack_sock(const struct sock *sock) +{ + return sock->sk_security + smack_blob_sizes.lbs_sock; +} + +#ifdef CONFIG_KEYS +static inline struct smack_known **smack_key(const struct key *key) +{ + return key->security + smack_blob_sizes.lbs_key; +} +#endif /* CONFIG_KEYS */ + /* * Is the directory transmuting? */ diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index eac7109be1db..8069f17d4404 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1606,7 +1606,7 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap, if (sock == NULL || sock->sk == NULL) return -EOPNOTSUPP; - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); if (strcmp(name, XATTR_SMACK_IPIN) == 0) isp = ssp->smk_in; @@ -1994,7 +1994,7 @@ static int smack_file_receive(struct file *file) if (inode->i_sb->s_magic == SOCKFS_MAGIC) { sock = SOCKET_I(inode); - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); tsp = smack_cred(current_cred()); /* * If the receiving process can't write to the @@ -2409,11 +2409,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode) static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) { struct smack_known *skp = smk_of_current(); - struct socket_smack *ssp; - - ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); - if (ssp == NULL) - return -ENOMEM; + struct socket_smack *ssp = smack_sock(sk); /* * Sockets created by kernel threads receive web label. @@ -2427,11 +2423,10 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) } ssp->smk_packet = NULL; - sk->sk_security = ssp; - return 0; } +#ifdef SMACK_IPV6_PORT_LABELING /** * smack_sk_free_security - Free a socket blob * @sk: the socket @@ -2440,7 +2435,6 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) */ static void smack_sk_free_security(struct sock *sk) { -#ifdef SMACK_IPV6_PORT_LABELING struct smk_port_label *spp; if (sk->sk_family == PF_INET6) { @@ -2453,9 +2447,8 @@ static void smack_sk_free_security(struct sock *sk) } rcu_read_unlock(); } -#endif - kfree(sk->sk_security); } +#endif /** * smack_sk_clone_security - Copy security context @@ -2466,8 +2459,8 @@ static void smack_sk_free_security(struct sock *sk) */ static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk) { - struct socket_smack *ssp_old = sk->sk_security; - struct socket_smack *ssp_new = newsk->sk_security; + struct socket_smack *ssp_old = smack_sock(sk); + struct socket_smack *ssp_new = smack_sock(newsk); *ssp_new = *ssp_old; } @@ -2583,7 +2576,7 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) */ static int smack_netlbl_add(struct sock *sk) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp = ssp->smk_out; int rc; @@ -2616,7 +2609,7 @@ static int smack_netlbl_add(struct sock *sk) */ static void smack_netlbl_delete(struct sock *sk) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); /* * Take the label off the socket if one is set. @@ -2648,7 +2641,7 @@ static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap) struct smack_known *skp; int rc = 0; struct smack_known *hkp; - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smk_audit_info ad; rcu_read_lock(); @@ -2721,7 +2714,7 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) { struct sock *sk = sock->sk; struct sockaddr_in6 *addr6; - struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); struct smk_port_label *spp; unsigned short port = 0; @@ -2809,7 +2802,7 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, int act) { struct smk_port_label *spp; - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp = NULL; unsigned short port; struct smack_known *object; @@ -2912,7 +2905,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name, if (sock == NULL || sock->sk == NULL) return -EOPNOTSUPP; - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); if (strcmp(name, XATTR_SMACK_IPIN) == 0) ssp->smk_in = skp; @@ -2960,7 +2953,7 @@ static int smack_socket_post_create(struct socket *sock, int family, * Sockets created by kernel threads receive web label. */ if (unlikely(current->flags & PF_KTHREAD)) { - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); ssp->smk_in = &smack_known_web; ssp->smk_out = &smack_known_web; } @@ -2985,8 +2978,8 @@ static int smack_socket_post_create(struct socket *sock, int family, static int smack_socket_socketpair(struct socket *socka, struct socket *sockb) { - struct socket_smack *asp = socka->sk->sk_security; - struct socket_smack *bsp = sockb->sk->sk_security; + struct socket_smack *asp = smack_sock(socka->sk); + struct socket_smack *bsp = smack_sock(sockb->sk); asp->smk_packet = bsp->smk_out; bsp->smk_packet = asp->smk_out; @@ -3049,7 +3042,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, if (__is_defined(SMACK_IPV6_SECMARK_LABELING)) rsp = smack_ipv6host_label(sip); if (rsp != NULL) { - struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); rc = smk_ipv6_check(ssp->smk_out, rsp, sip, SMK_CONNECTING); @@ -3844,9 +3837,9 @@ static int smack_unix_stream_connect(struct sock *sock, { struct smack_known *skp; struct smack_known *okp; - struct socket_smack *ssp = sock->sk_security; - struct socket_smack *osp = other->sk_security; - struct socket_smack *nsp = newsk->sk_security; + struct socket_smack *ssp = smack_sock(sock); + struct socket_smack *osp = smack_sock(other); + struct socket_smack *nsp = smack_sock(newsk); struct smk_audit_info ad; int rc = 0; #ifdef CONFIG_AUDIT @@ -3898,8 +3891,8 @@ static int smack_unix_stream_connect(struct sock *sock, */ static int smack_unix_may_send(struct socket *sock, struct socket *other) { - struct socket_smack *ssp = sock->sk->sk_security; - struct socket_smack *osp = other->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); + struct socket_smack *osp = smack_sock(other->sk); struct smk_audit_info ad; int rc; @@ -3936,7 +3929,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; #endif #ifdef SMACK_IPV6_SECMARK_LABELING - struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); struct smack_known *rsp; #endif int rc = 0; @@ -4148,7 +4141,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, netlbl_secattr_init(&secattr); if (sk) - ssp = sk->sk_security; + ssp = smack_sock(sk); if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) { skp = smack_from_secattr(&secattr, ssp); @@ -4170,7 +4163,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, */ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp = NULL; int rc = 0; struct smk_audit_info ad; @@ -4274,7 +4267,7 @@ static int smack_socket_getpeersec_stream(struct socket *sock, u32 slen = 1; int rc = 0; - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); if (ssp->smk_packet != NULL) { rcp = ssp->smk_packet->smk_known; slen = strlen(rcp) + 1; @@ -4324,7 +4317,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, switch (family) { case PF_UNIX: - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); s = ssp->smk_out->smk_secid; break; case PF_INET: @@ -4373,7 +4366,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent) (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) return; - ssp = sk->sk_security; + ssp = smack_sock(sk); ssp->smk_in = skp; ssp->smk_out = skp; /* cssp->smk_packet is already set in smack_inet_csk_clone() */ @@ -4393,7 +4386,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, { u16 family = sk->sk_family; struct smack_known *skp; - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct sockaddr_in addr; struct iphdr *hdr; struct smack_known *hskp; @@ -4479,7 +4472,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, static void smack_inet_csk_clone(struct sock *sk, const struct request_sock *req) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp; if (req->peer_secid != 0) { @@ -4511,24 +4504,14 @@ static void smack_inet_csk_clone(struct sock *sk, static int smack_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { + struct smack_known **blob = smack_key(key); struct smack_known *skp = smk_of_task(smack_cred(cred)); - key->security = skp; + *blob = skp; return 0; } /** - * smack_key_free - Clear the key security blob - * @key: the object - * - * Clear the blob pointer - */ -static void smack_key_free(struct key *key) -{ - key->security = NULL; -} - -/** * smack_key_permission - Smack access on a key * @key_ref: gets to the object * @cred: the credentials to use @@ -4541,6 +4524,8 @@ static int smack_key_permission(key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm) { + struct smack_known **blob; + struct smack_known *skp; struct key *keyp; struct smk_audit_info ad; struct smack_known *tkp = smk_of_task(smack_cred(cred)); @@ -4578,7 +4563,9 @@ static int smack_key_permission(key_ref_t key_ref, * If the key hasn't been initialized give it access so that * it may do so. */ - if (keyp->security == NULL) + blob = smack_key(keyp); + skp = *blob; + if (skp == NULL) return 0; /* * This should not occur @@ -4594,8 +4581,8 @@ static int smack_key_permission(key_ref_t key_ref, ad.a.u.key_struct.key = keyp->serial; ad.a.u.key_struct.key_desc = keyp->description; #endif - rc = smk_access(tkp, keyp->security, request, &ad); - rc = smk_bu_note("key access", tkp, keyp->security, request, rc); + rc = smk_access(tkp, skp, request, &ad); + rc = smk_bu_note("key access", tkp, skp, request, rc); return rc; } @@ -4610,11 +4597,12 @@ static int smack_key_permission(key_ref_t key_ref, */ static int smack_key_getsecurity(struct key *key, char **_buffer) { - struct smack_known *skp = key->security; + struct smack_known **blob = smack_key(key); + struct smack_known *skp = *blob; size_t length; char *copy; - if (key->security == NULL) { + if (skp == NULL) { *_buffer = NULL; return 0; } @@ -4922,10 +4910,10 @@ static int smack_inode_copy_up(struct dentry *dentry, struct cred **new) static int smack_inode_copy_up_xattr(struct dentry *src, const char *name) { /* - * Return 1 if this is the smack access Smack attribute. + * Return -ECANCELED if this is the smack access Smack attribute. */ - if (strcmp(name, XATTR_NAME_SMACK) == 0) - return 1; + if (!strcmp(name, XATTR_NAME_SMACK)) + return -ECANCELED; return -EOPNOTSUPP; } @@ -5048,7 +5036,9 @@ struct lsm_blob_sizes smack_blob_sizes __ro_after_init = { .lbs_file = sizeof(struct smack_known *), .lbs_inode = sizeof(struct inode_smack), .lbs_ipc = sizeof(struct smack_known *), + .lbs_key = sizeof(struct smack_known *), .lbs_msg_msg = sizeof(struct smack_known *), + .lbs_sock = sizeof(struct socket_smack), .lbs_superblock = sizeof(struct superblock_smack), .lbs_xattr_count = SMACK_INODE_INIT_XATTRS, }; @@ -5173,7 +5163,9 @@ static struct security_hook_list smack_hooks[] __ro_after_init = { LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream), LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram), LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security), +#ifdef SMACK_IPV6_PORT_LABELING LSM_HOOK_INIT(sk_free_security, smack_sk_free_security), +#endif LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security), LSM_HOOK_INIT(sock_graft, smack_sock_graft), LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request), @@ -5182,7 +5174,6 @@ static struct security_hook_list smack_hooks[] __ro_after_init = { /* key management security hooks */ #ifdef CONFIG_KEYS LSM_HOOK_INIT(key_alloc, smack_key_alloc), - LSM_HOOK_INIT(key_free, smack_key_free), LSM_HOOK_INIT(key_permission, smack_key_permission), LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity), #ifdef CONFIG_KEY_NOTIFICATIONS diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c index b945c1d3a743..bad71b7e648d 100644 --- a/security/smack/smack_netfilter.c +++ b/security/smack/smack_netfilter.c @@ -26,8 +26,8 @@ static unsigned int smack_ip_output(void *priv, struct socket_smack *ssp; struct smack_known *skp; - if (sk && sk->sk_security) { - ssp = sk->sk_security; + if (sk) { + ssp = smack_sock(sk); skp = ssp->smk_out; skb->secmark = skp->smk_secid; } diff --git a/tools/testing/selftests/lsm/lsm_list_modules_test.c b/tools/testing/selftests/lsm/lsm_list_modules_test.c index 06d24d4679a6..1cc8a977c711 100644 --- a/tools/testing/selftests/lsm/lsm_list_modules_test.c +++ b/tools/testing/selftests/lsm/lsm_list_modules_test.c @@ -128,6 +128,9 @@ TEST(correct_lsm_list_modules) case LSM_ID_EVM: name = "evm"; break; + case LSM_ID_IPE: + name = "ipe"; + break; default: name = "INVALID"; break; |