diff options
| -rw-r--r-- | Documentation/ABI/obsolete/sysfs-selinux-checkreqprot | 23 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 1 | ||||
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | security/selinux/Kconfig | 3 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 5 | ||||
| -rw-r--r-- | security/selinux/selinuxfs.c | 8 |
6 files changed, 40 insertions, 1 deletions
diff --git a/Documentation/ABI/obsolete/sysfs-selinux-checkreqprot b/Documentation/ABI/obsolete/sysfs-selinux-checkreqprot new file mode 100644 index 000000000000..49ed9c8fd1e5 --- /dev/null +++ b/Documentation/ABI/obsolete/sysfs-selinux-checkreqprot @@ -0,0 +1,23 @@ +What: /sys/fs/selinux/checkreqprot +Date: April 2005 (predates git) +KernelVersion: 2.6.12-rc2 (predates git) +Contact: selinux@vger.kernel.org +Description: + + The selinuxfs "checkreqprot" node allows SELinux to be configured + to check the protection requested by userspace for mmap/mprotect + calls instead of the actual protection applied by the kernel. + This was a compatibility mechanism for legacy userspace and + for the READ_IMPLIES_EXEC personality flag. However, if set to + 1, it weakens security by allowing mappings to be made executable + without authorization by policy. The default value of checkreqprot + at boot was changed starting in Linux v4.4 to 0 (i.e. check the + actual protection), and Android and Linux distributions have been + explicitly writing a "0" to /sys/fs/selinux/checkreqprot during + initialization for some time. Support for setting checkreqprot to 1 + will be removed in a future kernel release, at which point the kernel + will always cease using checkreqprot internally and will always + check the actual protections being applied upon mmap/mprotect calls. + The checkreqprot selinuxfs node will remain for backward compatibility + but will discard writes of the "0" value and will reject writes of the + "1" value when this mechanism is removed. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index dbc22d684627..ff1428d69b2d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -518,6 +518,7 @@ Default value is set via a kernel config option. Value can be changed at runtime via /sys/fs/selinux/checkreqprot. + Setting checkreqprot to 1 is deprecated. cio_ignore= [S390] See Documentation/s390/common_io.rst for details. diff --git a/MAINTAINERS b/MAINTAINERS index 38fe2f3f7b6f..0b370797e8a6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14986,6 +14986,7 @@ F: security/selinux/ F: scripts/selinux/ F: Documentation/admin-guide/LSM/SELinux.rst F: Documentation/ABI/obsolete/sysfs-selinux-disable +F: Documentation/ABI/obsolete/sysfs-selinux-checkreqprot SENSABLE PHANTOM M: Jiri Slaby <jirislaby@gmail.com> diff --git a/security/selinux/Kconfig b/security/selinux/Kconfig index 1014cb0ee956..9e921fc72538 100644 --- a/security/selinux/Kconfig +++ b/security/selinux/Kconfig @@ -88,6 +88,9 @@ config SECURITY_SELINUX_CHECKREQPROT_VALUE 'checkreqprot=' boot parameter. It may also be changed at runtime via /sys/fs/selinux/checkreqprot if authorized by policy. + WARNING: this option is deprecated and will be removed in a future + kernel release. + If you are unsure how to answer this question, answer 0. config SECURITY_SELINUX_SIDTAB_HASH_BITS diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b33cf155cc48..d7762264f262 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -142,8 +142,11 @@ static int __init checkreqprot_setup(char *str) { unsigned long checkreqprot; - if (!kstrtoul(str, 0, &checkreqprot)) + if (!kstrtoul(str, 0, &checkreqprot)) { selinux_checkreqprot_boot = checkreqprot ? 1 : 0; + if (checkreqprot) + pr_warn("SELinux: checkreqprot set to 1 via kernel parameter. This is deprecated and will be rejected in a future kernel release.\n"); + } return 1; } __setup("checkreqprot=", checkreqprot_setup); diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 79c710911a3c..d6566adc73a6 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -668,6 +668,14 @@ static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf, if (sscanf(page, "%u", &new_value) != 1) goto out; + if (new_value) { + char comm[sizeof(current->comm)]; + + memcpy(comm, current->comm, sizeof(comm)); + pr_warn_once("SELinux: %s (%d) set checkreqprot to 1. This is deprecated and will be rejected in a future kernel release.\n", + comm, current->pid); + } + fsi->state->checkreqprot = new_value ? 1 : 0; length = count; out: |