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2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-24locking/barriers: Convert users of lockless_dereference() to READ_ONCE()Will Deacon
READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-10seccomp: make function __get_seccomp_filter staticColin Ian King
The function __get_seccomp_filter is local to the source and does not need to be in global scope, so make it static. Cleans up sparse warning: symbol '__get_seccomp_filter' was not declared. Should it be static? Signed-off-by: Colin Ian King <colin.king@canonical.com> Fixes: 66a733ea6b61 ("seccomp: fix the usage of get/put_seccomp_filter() in seccomp_get_filter()") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2017-09-27seccomp: fix the usage of get/put_seccomp_filter() in seccomp_get_filter()Oleg Nesterov
As Chris explains, get_seccomp_filter() and put_seccomp_filter() can end up using different filters. Once we drop ->siglock it is possible for task->seccomp.filter to have been replaced by SECCOMP_FILTER_FLAG_TSYNC. Fixes: f8e529ed941b ("seccomp, ptrace: add support for dumping seccomp filters") Reported-by: Chris Salls <chrissalls5@gmail.com> Cc: stable@vger.kernel.org # needs s/refcount_/atomic_/ for v4.12 and earlier Signed-off-by: Oleg Nesterov <oleg@redhat.com> [tycho: add __get_seccomp_filter vs. open coding refcount_inc()] Signed-off-by: Tycho Andersen <tycho@docker.com> [kees: tweak commit log] Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Implement SECCOMP_RET_KILL_PROCESS actionKees Cook
Right now, SECCOMP_RET_KILL_THREAD (neé SECCOMP_RET_KILL) kills the current thread. There have been a few requests for this to kill the entire process (the thread group). This cannot be just changed (discovered when adding coredump support since coredumping kills the entire process) because there are userspace programs depending on the thread-kill behavior. Instead, implement SECCOMP_RET_KILL_PROCESS, which is 0x80000000, and can be processed as "-1" by the kernel, below the existing RET_KILL that is ABI-set to "0". For userspace, SECCOMP_RET_ACTION_FULL is added to expand the mask to the signed bit. Old userspace using the SECCOMP_RET_ACTION mask will see SECCOMP_RET_KILL_PROCESS as 0 still, but this would only be visible when examining the siginfo in a core dump from a RET_KILL_*, where it will think it was thread-killed instead of process-killed. Attempts to introduce this behavior via other ways (filter flags, seccomp struct flags, masked RET_DATA bits) all come with weird side-effects and baggage. This change preserves the central behavioral expectations of the seccomp filter engine without putting too great a burden on changes needed in userspace to use the new action. The new action is discoverable by userspace through either the new actions_avail sysctl or through the SECCOMP_GET_ACTION_AVAIL seccomp operation. If used without checking for availability, old kernels will treat RET_KILL_PROCESS as RET_KILL_THREAD (since the old mask will produce RET_KILL_THREAD). Cc: Paul Moore <paul@paul-moore.com> Cc: Fabricio Voznika <fvoznika@google.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Introduce SECCOMP_RET_KILL_PROCESSKees Cook
This introduces the BPF return value for SECCOMP_RET_KILL_PROCESS to kill an entire process. This cannot yet be reached by seccomp, but it changes the default-kill behavior (for unknown return values) from kill-thread to kill-process. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Rename SECCOMP_RET_KILL to SECCOMP_RET_KILL_THREADKees Cook
In preparation for adding SECCOMP_RET_KILL_PROCESS, rename SECCOMP_RET_KILL to the more accurate SECCOMP_RET_KILL_THREAD. The existing selftest values are intentionally left as SECCOMP_RET_KILL just to be sure we're exercising the alias. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Action to log before allowingTyler Hicks
Add a new action, SECCOMP_RET_LOG, that logs a syscall before allowing the syscall. At the implementation level, this action is identical to the existing SECCOMP_RET_ALLOW action. However, it can be very useful when initially developing a seccomp filter for an application. The developer can set the default action to be SECCOMP_RET_LOG, maybe mark any obviously needed syscalls with SECCOMP_RET_ALLOW, and then put the application through its paces. A list of syscalls that triggered the default action (SECCOMP_RET_LOG) can be easily gleaned from the logs and that list can be used to build the syscall whitelist. Finally, the developer can change the default action to the desired value. This provides a more friendly experience than seeing the application get killed, then updating the filter and rebuilding the app, seeing the application get killed due to a different syscall, then updating the filter and rebuilding the app, etc. The functionality is similar to what's supported by the various LSMs. SELinux has permissive mode, AppArmor has complain mode, SMACK has bring-up mode, etc. SECCOMP_RET_LOG is given a lower value than SECCOMP_RET_ALLOW as allow while logging is slightly more restrictive than quietly allowing. Unfortunately, the tests added for SECCOMP_RET_LOG are not capable of inspecting the audit log to verify that the syscall was logged. With this patch, the logic for deciding if an action will be logged is: if action == RET_ALLOW: do not log else if action == RET_KILL && RET_KILL in actions_logged: log else if action == RET_LOG && RET_LOG in actions_logged: log else if filter-requests-logging && action in actions_logged: log else if audit_enabled && process-is-being-audited: log else: do not log Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Filter flag to log all actions except SECCOMP_RET_ALLOWTyler Hicks
Add a new filter flag, SECCOMP_FILTER_FLAG_LOG, that enables logging for all actions except for SECCOMP_RET_ALLOW for the given filter. SECCOMP_RET_KILL actions are always logged, when "kill" is in the actions_logged sysctl, and SECCOMP_RET_ALLOW actions are never logged, regardless of this flag. This flag can be used to create noisy filters that result in all non-allowed actions to be logged. A process may have one noisy filter, which is loaded with this flag, as well as a quiet filter that's not loaded with this flag. This allows for the actions in a set of filters to be selectively conveyed to the admin. Since a system could have a large number of allocated seccomp_filter structs, struct packing was taken in consideration. On 64 bit x86, the new log member takes up one byte of an existing four byte hole in the struct. On 32 bit x86, the new log member creates a new four byte hole (unavoidable) and consumes one of those bytes. Unfortunately, the tests added for SECCOMP_FILTER_FLAG_LOG are not capable of inspecting the audit log to verify that the actions taken in the filter were logged. With this patch, the logic for deciding if an action will be logged is: if action == RET_ALLOW: do not log else if action == RET_KILL && RET_KILL in actions_logged: log else if filter-requests-logging && action in actions_logged: log else if audit_enabled && process-is-being-audited: log else: do not log Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Sysctl to configure actions that are allowed to be loggedTyler Hicks
Adminstrators can write to this sysctl to set the seccomp actions that are allowed to be logged. Any actions not found in this sysctl will not be logged. For example, all SECCOMP_RET_KILL, SECCOMP_RET_TRAP, and SECCOMP_RET_ERRNO actions would be loggable if "kill trap errno" were written to the sysctl. SECCOMP_RET_TRACE actions would not be logged since its string representation ("trace") wasn't present in the sysctl value. The path to the sysctl is: /proc/sys/kernel/seccomp/actions_logged The actions_avail sysctl can be read to discover the valid action names that can be written to the actions_logged sysctl with the exception of "allow". SECCOMP_RET_ALLOW actions cannot be configured for logging. The default setting for the sysctl is to allow all actions to be logged except SECCOMP_RET_ALLOW. While only SECCOMP_RET_KILL actions are currently logged, an upcoming patch will allow applications to request additional actions to be logged. There's one important exception to this sysctl. If a task is specifically being audited, meaning that an audit context has been allocated for the task, seccomp will log all actions other than SECCOMP_RET_ALLOW despite the value of actions_logged. This exception preserves the existing auditing behavior of tasks with an allocated audit context. With this patch, the logic for deciding if an action will be logged is: if action == RET_ALLOW: do not log else if action == RET_KILL && RET_KILL in actions_logged: log else if audit_enabled && task-is-being-audited: log else: do not log Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Operation for checking if an action is availableTyler Hicks
Userspace code that needs to check if the kernel supports a given action may not be able to use the /proc/sys/kernel/seccomp/actions_avail sysctl. The process may be running in a sandbox and, therefore, sufficient filesystem access may not be available. This patch adds an operation to the seccomp(2) syscall that allows userspace code to ask the kernel if a given action is available. If the action is supported by the kernel, 0 is returned. If the action is not supported by the kernel, -1 is returned with errno set to -EOPNOTSUPP. If this check is attempted on a kernel that doesn't support this new operation, -1 is returned with errno set to -EINVAL meaning that userspace code will have the ability to differentiate between the two error cases. Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Suggested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Sysctl to display available actionsTyler Hicks
This patch creates a read-only sysctl containing an ordered list of seccomp actions that the kernel supports. The ordering, from left to right, is the lowest action value (kill) to the highest action value (allow). Currently, a read of the sysctl file would return "kill trap errno trace allow". The contents of this sysctl file can be useful for userspace code as well as the system administrator. The path to the sysctl is: /proc/sys/kernel/seccomp/actions_avail libseccomp and other userspace code can easily determine which actions the current kernel supports. The set of actions supported by the current kernel may be different than the set of action macros found in kernel headers that were installed where the userspace code was built. In addition, this sysctl will allow system administrators to know which actions are supported by the kernel and make it easier to configure exactly what seccomp logs through the audit subsystem. Support for this level of logging configuration will come in a future patch. Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-08-14seccomp: Provide matching filter for introspectionKees Cook
Both the upcoming logging improvements and changes to RET_KILL will need to know which filter a given seccomp return value originated from. In order to delay logic processing of result until after the seccomp loop, this adds a single pointer assignment on matches. This will allow both log and RET_KILL logic to work off the filter rather than doing more expensive tests inside the time-critical run_filters loop. Running tight cycles of getpid() with filters attached shows no measurable difference in speed. Suggested-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
2017-06-26seccomp: Switch from atomic_t to recount_tKees Cook
This switches the seccomp usage tracking from atomic_t to refcount_t to gain refcount overflow protections. Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: David Windsor <dwindsor@gmail.com> Cc: Hans Liljestrand <hans.liljestrand@aalto.fi> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-06-26seccomp: Clean up core dump logicKees Cook
This just cleans up the core dumping logic to avoid the braces around the RET_KILL case. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-23seccomp: Only dump core when single-threadedKees Cook
The SECCOMP_RET_KILL filter return code has always killed the current thread, not the entire process. Changing this as a side-effect of dumping core isn't a safe thing to do (a few test suites have already flagged this behavioral change). Instead, restore the RET_KILL semantics, but still dump core when a RET_KILL delivers SIGSYS to a single-threaded process. Fixes: b25e67161c29 ("seccomp: dump core when using SECCOMP_RET_KILL") Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-01-23seccomp: dump core when using SECCOMP_RET_KILLMike Frysinger
The SECCOMP_RET_KILL mode is documented as immediately killing the process as if a SIGSYS had been sent and not caught (similar to a SIGKILL). However, a SIGSYS is documented as triggering a coredump which does not happen today. This has the advantage of being able to more easily debug a process that fails a seccomp filter. Today, most apps need to recompile and change their filter in order to get detailed info out, or manually run things through strace, or enable detailed kernel auditing. Now we get coredumps that fit into existing system-wide crash reporting setups. From a security pov, this shouldn't be a problem. Unhandled signals can already be sent externally which trigger a coredump independent of the status of the seccomp filter. The act of dumping core itself does not cause change in execution of the program. URL: https://crbug.com/676357 Signed-off-by: Mike Frysinger <vapier@chromium.org> Acked-by: Jorge Lucangeli Obes <jorgelo@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-12-14Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Generally pretty quiet for this release. Highlights: Yama: - allow ptrace access for original parent after re-parenting TPM: - add documentation - many bugfixes & cleanups - define a generic open() method for ascii & bios measurements Integrity: - Harden against malformed xattrs SELinux: - bugfixes & cleanups Smack: - Remove unnecessary smack_known_invalid label - Do not apply star label in smack_setprocattr hook - parse mnt opts after privileges check (fixes unpriv DoS vuln)" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (56 commits) Yama: allow access for the current ptrace parent tpm: adjust return value of tpm_read_log tpm: vtpm_proxy: conditionally call tpm_chip_unregister tpm: Fix handling of missing event log tpm: Check the bios_dir entry for NULL before accessing it tpm: return -ENODEV if np is not set tpm: cleanup of printk error messages tpm: replace of_find_node_by_name() with dev of_node property tpm: redefine read_log() to handle ACPI/OF at runtime tpm: fix the missing .owner in tpm_bios_measurements_ops tpm: have event log use the tpm_chip tpm: drop tpm1_chip_register(/unregister) tpm: replace dynamically allocated bios_dir with a static array tpm: replace symbolic permission with octal for securityfs files char: tpm: fix kerneldoc tpm2_unseal_trusted name typo tpm_tis: Allow tpm_tis to be bound using DT tpm, tpm_vtpm_proxy: add kdoc comments for VTPM_PROXY_IOC_NEW_DEV tpm: Only call pm_runtime_get_sync if device has a parent tpm: define a generic open() method for ascii & bios measurements Documentation: tpm: add the Physical TPM device tree binding documentation ...
2016-11-27bpf: drop unnecessary context cast from BPF_PROG_RUNDaniel Borkmann
Since long already bpf_func is not only about struct sk_buff * as input anymore. Make it generic as void *, so that callers don't need to cast for it each time they call BPF_PROG_RUN(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-01seccomp: Fix documentationMickaël Salaün
Fix struct seccomp_filter and seccomp_run_filters() signatures. Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: James Morris <jmorris@namei.org> Cc: Kees Cook <keescook@chromium.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-30seccomp: Fix tracer exit notifications during fatal signalsKees Cook
This fixes a ptrace vs fatal pending signals bug as manifested in seccomp now that seccomp was reordered to happen after ptrace. The short version is that seccomp should not attempt to call do_exit() while fatal signals are pending under a tracer. The existing code was trying to be as defensively paranoid as possible, but it now ends up confusing ptrace. Instead, the syscall can just be skipped (which solves the original concern that the do_exit() was addressing) and normal signal handling, tracer notification, and process death can happen. Paraphrasing from the original bug report: If a tracee task is in a PTRACE_EVENT_SECCOMP trap, or has been resumed after such a trap but not yet been scheduled, and another task in the thread-group calls exit_group(), then the tracee task exits without the ptracer receiving a PTRACE_EVENT_EXIT notification. Test case here: https://gist.github.com/khuey/3c43ac247c72cef8c956ca73281c9be7 The bug happens because when __seccomp_filter() detects fatal_signal_pending(), it calls do_exit() without dequeuing the fatal signal. When do_exit() sends the PTRACE_EVENT_EXIT notification and that task is descheduled, __schedule() notices that there is a fatal signal pending and changes its state from TASK_TRACED to TASK_RUNNING. That prevents the ptracer's waitpid() from returning the ptrace event. A more detailed analysis is here: https://github.com/mozilla/rr/issues/1762#issuecomment-237396255. Reported-by: Robert O'Callahan <robert@ocallahan.org> Reported-by: Kyle Huey <khuey@kylehuey.com> Tested-by: Kyle Huey <khuey@kylehuey.com> Fixes: 93e35efb8de4 ("x86/ptrace: run seccomp after ptrace") Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com>
2016-08-04tree-wide: replace config_enabled() with IS_ENABLED()Masahiro Yamada
The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-14seccomp: recheck the syscall after RET_TRACEKees Cook
When RET_TRACE triggers, a tracer may change a syscall into something that should be filtered by seccomp. This re-runs seccomp after a trace event to make sure things continue to pass. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org>
2016-06-14seccomp: remove 2-phase APIKees Cook
Since nothing is using the 2-phase API, and it adds more complexity than benefit, remove it. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org>
2016-06-14seccomp: Add a seccomp_data parameter secure_computing()Andy Lutomirski
Currently, if arch code wants to supply seccomp_data directly to seccomp (which is generally much faster than having seccomp do it using the syscall_get_xyz() API), it has to use the two-phase seccomp hooks. Add it to the easy hooks, too. Cc: linux-arch@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-05-19Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.7. Here's the summary of the changes: - ATH79: Support for DTB passuing using the UHI boot protocol - ATH79: Remove support for builtin DTB. - ATH79: Add zboot debug serial support. - ATH79: Add initial support for Dragino MS14 (Dragine 2), Onion Omega and DPT-Module. - ATH79: Update devicetree clock support for AR9132 and AR9331. - ATH79: Cleanup the DT code. - ATH79: Support newer SOCs in ath79_ddr_ctrl_init. - ATH79: Fix regression in PCI window initialization. - BCM47xx: Move SPROM driver to drivers/firmware/ - BCM63xx: Enable partition parser in defconfig. - BMIPS: BMIPS5000 has I cache filing from D cache - BMIPS: BMIPS: Add cpu-feature-overrides.h - BMIPS: Add Whirlwind support - BMIPS: Adjust mips-hpt-frequency for BCM7435 - BMIPS: Remove maxcpus from BCM97435SVMB DTS - BMIPS: Add missing 7038 L1 register cells to BCM7435 - BMIPS: Various tweaks to initialization code. - BMIPS: Enable partition parser in defconfig. - BMIPS: Cache tweaks. - BMIPS: Add UART, I2C and SATA devices to DT. - BMIPS: Add BCM6358 and BCM63268support - BMIPS: Add device tree example for BCM6358. - BMIPS: Improve Improve BCM6328 and BCM6368 device trees - Lantiq: Add support for device tree file from boot loader - Lantiq: Allow build with no built-in DT. - Loongson 3: Reserve 32MB for RS780E integrated GPU. - Loongson 3: Fix build error after ld-version.sh modification - Loongson 3: Move chipset ACPI code from drivers to arch. - Loongson 3: Speedup irq processing. - Loongson 3: Add basic Loongson 3A support. - Loongson 3: Set cache flush handlers to nop. - Loongson 3: Invalidate special TLBs when needed. - Loongson 3: Fast TLB refill handler. - MT7620: Fallback strategy for invalid syscfg0. - Netlogic: Fix CP0_EBASE redefinition warnings - Octeon: Initialization fixes - Octeon: Add DTS files for the D-Link DSR-1000N and EdgeRouter Lite - Octeon: Enable add Octeon-drivers in cavium_octeon_defconfig - Octeon: Correctly handle endian-swapped initramfs images. - Octeon: Support CN73xx, CN75xx and CN78xx. - Octeon: Remove dead code from cvmx-sysinfo. - Octeon: Extend number of supported CPUs past 32. - Octeon: Remove some code limiting NR_IRQS to 255. - Octeon: Simplify octeon_irq_ciu_gpio_set_type. - Octeon: Mark some functions __init in smp.c - Octeon: Octeon: Add Octeon III CN7xxx interface detection - PIC32: Add serial driver and bindings for it. - PIC32: Add PIC32 deadman timer driver and bindings. - PIC32: Add PIC32 clock timer driver and bindings. - Pistachio: Determine SoC revision during boot - Sibyte: Fix Kconfig dependencies of SIBYTE_BUS_WATCHER. - Sibyte: Strip redundant comments from bcm1480_regs.h. - Panic immediately if panic_on_oops is set. - module: fix incorrect IS_ERR_VALUE macro usage. - module: Make consistent use of pr_* - Remove no longer needed work_on_cpu() call. - Remove CONFIG_IPV6_PRIVACY from defconfigs. - Fix registers of non-crashing CPUs in dumps. - Handle MIPSisms in new vmcore_elf32_check_arch. - Select CONFIG_HANDLE_DOMAIN_IRQ and make it work. - Allow RIXI to be used on non-R2 or R6 cores. - Reserve nosave data for hibernation - Fix siginfo.h to use strict POSIX types. - Don't unwind user mode with EVA. - Fix watchpoint restoration - Ptrace watchpoints for R6. - Sync icache when it fills from dcache - I6400 I-cache fills from dcache. - Various MSA fixes. - Cleanup MIPS_CPU_* definitions. - Signal: Move generic copy_siginfo to signal.h - Signal: Fix uapi include in exported asm/siginfo.h - Timer fixes for sake of KVM. - XPA TLB refill fixes. - Treat perf counter feature - Update John Crispin's email address - Add PIC32 watchdog and bindings. - Handle R10000 LL/SC bug in set_pte() - cpufreq: Various fixes for Longson1. - R6: Fix R2 emulation. - mathemu: Cosmetic fix to ADDIUPC emulation, plenty of other small fixes - ELF: ABI and FP fixes. - Allow for relocatable kernel and use that to support KASLR. - Fix CPC_BASE_ADDR mask - Plenty fo smp-cps, CM, R6 and M6250 fixes. - Make reset_control_ops const. - Fix kernel command line handling of leading whitespace. - Cleanups to cache handling. - Add brcm, bcm6345-l1-intc device tree bindings. - Use generic clkdev.h header - Remove CLK_IS_ROOT usage. - Misc small cleanups. - CM: Fix compilation error when !MIPS_CM - oprofile: Fix a preemption issue - Detect DSP ASE v3 support:1" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (275 commits) MIPS: pic32mzda: fix getting timer clock rate. MIPS: ath79: fix regression in PCI window initialization MIPS: ath79: make ath79_ddr_ctrl_init() compatible for newer SoCs MIPS: Fix VZ probe gas errors with binutils <2.24 MIPS: perf: Fix I6400 event numbers MIPS: DEC: Export `ioasic_ssr_lock' to modules MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC MIPS: CM: Fix compilation error when !MIPS_CM MIPS: Fix genvdso error on rebuild USB: ohci-jz4740: Remove obsolete driver MIPS: JZ4740: Probe OHCI platform device via DT MIPS: JZ4740: Qi LB60: Remove support for AVT2 variant MIPS: pistachio: Determine SoC revision during boot MIPS: BMIPS: Adjust mips-hpt-frequency for BCM7435 mips: mt7620: fallback to SDRAM when syscfg0 does not have a valid value for the memory type MIPS: Prevent "restoration" of MSA context in non-MSA kernels MIPS: cevt-r4k: Dynamically calculate min_delta_ns MIPS: malta-time: Take seconds into account MIPS: malta-time: Start GIC count before syncing to RTC MIPS: Force CPUs to lose FP context during mode switches ...
2016-05-13secomp: Constify mode1 syscall whitelistMatt Redfearn
These values are constant and should be marked as such. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Will Drewry <wad@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: IMG-MIPSLinuxKerneldevelopers@imgtec.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12979/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13seccomp: Get compat syscalls from asm-generic headerMatt Redfearn
Move retrieval of compat syscall numbers into inline function defined in asm-generic header so that arches may override it. [ralf@linux-mips.org: Resolve merge conflict.] Suggested-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: IMG-MIPSLinuxKerneldevelopers@imgtec.com Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12978/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-04seccomp: Fix comment typoMickaël Salaün
Drop accidentally repeated word in comment. Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org>
2016-03-22seccomp: check in_compat_syscall, not is_compat_task, in strict modeAndy Lutomirski
Seccomp wants to know the syscall bitness, not the caller task bitness, when it selects the syscall whitelist. As far as I know, this makes no difference on any architecture, so it's not a security problem. (It generates identical code everywhere except sparc, and, on sparc, the syscall numbering is the same for both ABIs.) Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-27seccomp: always propagate NO_NEW_PRIVS on tsyncJann Horn
Before this patch, a process with some permissive seccomp filter that was applied by root without NO_NEW_PRIVS was able to add more filters to itself without setting NO_NEW_PRIVS by setting the new filter from a throwaway thread with NO_NEW_PRIVS. Signed-off-by: Jann Horn <jann@thejh.net> Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2015-10-27seccomp, ptrace: add support for dumping seccomp filtersTycho Andersen
This patch adds support for dumping a process' (classic BPF) seccomp filters via ptrace. PTRACE_SECCOMP_GET_FILTER allows the tracer to dump the user's classic BPF seccomp filters. addr should be an integer which represents the ith seccomp filter (0 is the most recently installed filter). data should be a struct sock_filter * with enough room for the ith filter, or NULL, in which case the filter is not saved. The return value for this command is the number of BPF instructions the program represents, or negative in the case of errors. Command specific errors are ENOENT: which indicates that there is no ith filter in this seccomp tree, and EMEDIUMTYPE, which indicates that the ith filter was not installed as a classic BPF filter. A caveat with this approach is that there is no way to get explicitly at the heirarchy of seccomp filters, and users need to memcmp() filters to decide which are inherited. This means that a task which installs two of the same filter can potentially confuse users of this interface. v2: * make save_orig const * check that the orig_prog exists (not necessary right now, but when grows eBPF support it will be) * s/n/filter_off and make it an unsigned long to match ptrace * count "down" the tree instead of "up" when passing a filter offset v3: * don't take the current task's lock for inspecting its seccomp mode * use a 0x42** constant for the ptrace command value v4: * don't copy to userspace while holding spinlocks v5: * add another condition to WARN_ON v6: * rebase on net-next Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> CC: Will Drewry <wad@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> CC: Andy Lutomirski <luto@amacapital.net> CC: Pavel Emelyanov <xemul@parallels.com> CC: Serge E. Hallyn <serge.hallyn@ubuntu.com> CC: Alexei Starovoitov <ast@kernel.org> CC: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05bpf, seccomp: prepare for upcoming criu supportDaniel Borkmann
The current ongoing effort to dump existing cBPF seccomp filters back to user space requires to hold the pre-transformed instructions like we do in case of socket filters from sk_attach_filter() side, so they can be reloaded in original form at a later point in time by utilities such as criu. To prepare for this, simply extend the bpf_prog_create_from_user() API to hold a flag that tells whether we should store the original or not. Also, fanout filters could make use of that in future for things like diag. While fanout filters already use bpf_prog_destroy(), move seccomp over to them as well to handle original programs when present. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Tycho Andersen <tycho.andersen@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Tycho Andersen <tycho.andersen@canonical.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20Merge tag 'seccomp-next' of ↵James Morris
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into next
2015-07-15seccomp: swap hard-coded zeros to defined nameKees Cook
For clarity, if CONFIG_SECCOMP isn't defined, seccomp_mode() is returning "disabled". This makes that more clear, along with another 0-use, and results in no operational change. Signed-off-by: Kees Cook <keescook@chromium.org>
2015-07-15seccomp: add ptrace options for suspend/resumeTycho Andersen
This patch is the first step in enabling checkpoint/restore of processes with seccomp enabled. One of the things CRIU does while dumping tasks is inject code into them via ptrace to collect information that is only available to the process itself. However, if we are in a seccomp mode where these processes are prohibited from making these syscalls, then what CRIU does kills the task. This patch adds a new ptrace option, PTRACE_O_SUSPEND_SECCOMP, that enables a task from the init user namespace which has CAP_SYS_ADMIN and no seccomp filters to disable (and re-enable) seccomp filters for another task so that they can be successfully dumped (and restored). We restrict the set of processes that can disable seccomp through ptrace because although today ptrace can be used to bypass seccomp, there is some discussion of closing this loophole in the future and we would like this patch to not depend on that behavior and be future proofed for when it is removed. Note that seccomp can be suspended before any filters are actually installed; this behavior is useful on criu restore, so that we can suspend seccomp, restore the filters, unmap our restore code from the restored process' address space, and then resume the task by detaching and have the filters resumed as well. v2 changes: * require that the tracer have no seccomp filters installed * drop TIF_NOTSC manipulation from the patch * change from ptrace command to a ptrace option and use this ptrace option as the flag to check. This means that as soon as the tracer detaches/dies, seccomp is re-enabled and as a corrollary that one can not disable seccomp across PTRACE_ATTACHs. v3 changes: * get rid of various #ifdefs everywhere * report more sensible errors when PTRACE_O_SUSPEND_SECCOMP is incorrectly used v4 changes: * get rid of may_suspend_seccomp() in favor of a capable() check in ptrace directly v5 changes: * check that seccomp is not enabled (or suspended) on the tracer Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com> CC: Will Drewry <wad@chromium.org> CC: Roland McGrath <roland@hack.frob.com> CC: Pavel Emelyanov <xemul@parallels.com> CC: Serge E. Hallyn <serge.hallyn@ubuntu.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> [kees: access seccomp.mode through seccomp_mode() instead] Signed-off-by: Kees Cook <keescook@chromium.org>
2015-07-15seccomp: Replace smp_read_barrier_depends() with lockless_dereference()Pranith Kumar
Recently lockless_dereference() was added which can be used in place of hard-coding smp_read_barrier_depends(). The following PATCH makes the change. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2015-05-09seccomp, filter: add and use bpf_prog_create_from_user from seccompDaniel Borkmann
Seccomp has always been a special candidate when it comes to preparation of its filters in seccomp_prepare_filter(). Due to the extra checks and filter rewrite it partially duplicates code and has BPF internals exposed. This patch adds a generic API inside the BPF code code that seccomp can use and thus keep it's filter preparation code minimal and better maintainable. The other side-effect is that now classic JITs can add seccomp support as well by only providing a BPF_LDX | BPF_W | BPF_ABS translation. Tested with seccomp and BPF test suites. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Nicolas Schichan <nschichan@freebox.fr> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Kees Cook <keescook@chromium.org> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09seccomp: simplify seccomp_prepare_filter and reuse bpf_prepare_filterNicolas Schichan
Remove the calls to bpf_check_classic(), bpf_convert_filter() and bpf_migrate_runtime() and let bpf_prepare_filter() take care of that instead. seccomp_check_filter() is passed to bpf_prepare_filter() so that it gets called from there, after bpf_check_classic(). We can now remove exposure of two internal classic BPF functions previously used by seccomp. The export of bpf_check_classic() symbol, previously known as sk_chk_filter(), was there since pre git times, and no in-tree module was using it, therefore remove it. Joint work with Daniel Borkmann. Signed-off-by: Nicolas Schichan <nschichan@freebox.fr> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Kees Cook <keescook@chromium.org> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-17seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNOKees Cook
The value resulting from the SECCOMP_RET_DATA mask could exceed MAX_ERRNO when setting errno during a SECCOMP_RET_ERRNO filter action. This makes sure we have a reliable value being set, so that an invalid errno will not be ignored by userspace. Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Dmitry V. Levin <ldv@altlinux.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14Merge branch 'x86-seccomp-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 seccomp changes from Ingo Molnar: "This tree includes x86 seccomp filter speedups and related preparatory work, which touches core seccomp facilities as well. The main idea is to split seccomp into two phases, to be able to enter a simple fast path for syscalls with ptrace side effects. There's no substantial user-visible (and ABI) effects expected from this, except a change in how we emit a better audit record for SECCOMP_RET_TRACE events" * 'x86-seccomp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86_64, entry: Use split-phase syscall_trace_enter for 64-bit syscalls x86_64, entry: Treat regs->ax the same in fastpath and slowpath syscalls x86: Split syscall_trace_enter into two phases x86, entry: Only call user_exit if TIF_NOHZ x86, x32, audit: Fix x32's AUDIT_ARCH wrt audit seccomp: Document two-phase seccomp and arch-provided seccomp_data seccomp: Allow arch code to provide seccomp_data seccomp: Refactor the filter callback and the API seccomp,x86,arm,mips,s390: Remove nr parameter from secure_computing
2014-09-05net: bpf: make eBPF interpreter images read-onlyDaniel Borkmann
With eBPF getting more extended and exposure to user space is on it's way, hardening the memory range the interpreter uses to steer its command flow seems appropriate. This patch moves the to be interpreted bytecode to read-only pages. In case we execute a corrupted BPF interpreter image for some reason e.g. caused by an attacker which got past a verifier stage, it would not only provide arbitrary read/write memory access but arbitrary function calls as well. After setting up the BPF interpreter image, its contents do not change until destruction time, thus we can setup the image on immutable made pages in order to mitigate modifications to that code. The idea is derived from commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit against spraying attacks"). This is possible because bpf_prog is not part of sk_filter anymore. After setup bpf_prog cannot be altered during its life-time. This prevents any modifications to the entire bpf_prog structure (incl. function/JIT image pointer). Every eBPF program (including classic BPF that are migrated) have to call bpf_prog_select_runtime() to select either interpreter or a JIT image as a last setup step, and they all are being freed via bpf_prog_free(), including non-JIT. Therefore, we can easily integrate this into the eBPF life-time, plus since we directly allocate a bpf_prog, we have no performance penalty. Tested with seccomp and test_bpf testsuite in JIT/non-JIT mode and manual inspection of kernel_page_tables. Brad Spengler proposed the same idea via Twitter during development of this patch. Joint work with Hannes Frederic Sowa. Suggested-by: Brad Spengler <spender@grsecurity.net> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Kees Cook <keescook@chromium.org> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-03seccomp: Allow arch code to provide seccomp_dataAndy Lutomirski
populate_seccomp_data is expensive: it works by inspecting task_pt_regs and various other bits to piece together all the information, and it's does so in multiple partially redundant steps. Arch-specific code in the syscall entry path can do much better. Admittedly this adds a bit of additional room for error, but the speedup should be worth it. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-09-03seccomp: Refactor the filter callback and the APIAndy Lutomirski
The reason I did this is to add a seccomp API that will be usable for an x86 fast path. The x86 entry code needs to use a rather expensive slow path for a syscall that might be visible to things like ptrace. By splitting seccomp into two phases, we can check whether we need the slow path and then use the fast path in if the filter allows the syscall or just returns some errno. As a side effect, I think the new code is much easier to understand than the old code. This has one user-visible effect: the audit record written for SECCOMP_RET_TRACE is now a simple indication that SECCOMP_RET_TRACE happened. It used to depend in a complicated way on what the tracer did. I couldn't make much sense of it. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-09-03seccomp,x86,arm,mips,s390: Remove nr parameter from secure_computingAndy Lutomirski
The secure_computing function took a syscall number parameter, but it only paid any attention to that parameter if seccomp mode 1 was enabled. Rather than coming up with a kludge to get the parameter to work in mode 2, just remove the parameter. To avoid churn in arches that don't have seccomp filters (and may not even support syscall_get_nr right now), this leaves the parameter in secure_computing_strict, which is now a real function. For ARM, this is a bit ugly due to the fact that ARM conditionally supports seccomp filters. Fixing that would probably only be a couple of lines of code, but it should be coordinated with the audit maintainers. This will be a slight slowdown on some arches. The right fix is to pass in all of seccomp_data instead of trying to make just the syscall nr part be fast. This is a prerequisite for making two-phase seccomp work cleanly. Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-08-11seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lockGuenter Roeck
Current upstream kernel hangs with mips and powerpc targets in uniprocessor mode if SECCOMP is configured. Bisect points to commit dbd952127d11 ("seccomp: introduce writer locking"). Turns out that code such as BUG_ON(!spin_is_locked(&list_lock)); can not be used in uniprocessor mode because spin_is_locked() always returns false in this configuration, and that assert_spin_locked() exists for that very purpose and must be used instead. Fixes: dbd952127d11 ("seccomp: introduce writer locking") Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-08-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: "Highlights: 1) Steady transitioning of the BPF instructure to a generic spot so all kernel subsystems can make use of it, from Alexei Starovoitov. 2) SFC driver supports busy polling, from Alexandre Rames. 3) Take advantage of hash table in UDP multicast delivery, from David Held. 4) Lighten locking, in particular by getting rid of the LRU lists, in inet frag handling. From Florian Westphal. 5) Add support for various RFC6458 control messages in SCTP, from Geir Ola Vaagland. 6) Allow to filter bridge forwarding database dumps by device, from Jamal Hadi Salim. 7) virtio-net also now supports busy polling, from Jason Wang. 8) Some low level optimization tweaks in pktgen from Jesper Dangaard Brouer. 9) Add support for ipv6 address generation modes, so that userland can have some input into the process. From Jiri Pirko. 10) Consolidate common TCP connection request code in ipv4 and ipv6, from Octavian Purdila. 11) New ARP packet logger in netfilter, from Pablo Neira Ayuso. 12) Generic resizable RCU hash table, with intial users in netlink and nftables. From Thomas Graf. 13) Maintain a name assignment type so that userspace can see where a network device name came from (enumerated by kernel, assigned explicitly by userspace, etc.) From Tom Gundersen. 14) Automatic flow label generation on transmit in ipv6, from Tom Herbert. 15) New packet timestamping facilities from Willem de Bruijn, meant to assist in measuring latencies going into/out-of the packet scheduler, latency from TCP data transmission to ACK, etc" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1536 commits) cxgb4 : Disable recursive mailbox commands when enabling vi net: reduce USB network driver config options. tg3: Modify tg3_tso_bug() to handle multiple TX rings amd-xgbe: Perform phy connect/disconnect at dev open/stop amd-xgbe: Use dma_set_mask_and_coherent to set DMA mask net: sun4i-emac: fix memory leak on bad packet sctp: fix possible seqlock seadlock in sctp_packet_transmit() Revert "net: phy: Set the driver when registering an MDIO bus device" cxgb4vf: Turn off SGE RX/TX Callback Timers and interrupts in PCI shutdown routine team: Simplify return path of team_newlink bridge: Update outdated comment on promiscuous mode net-timestamp: ACK timestamp for bytestreams net-timestamp: TCP timestamping net-timestamp: SCHED timestamp on entering packet scheduler net-timestamp: add key to disambiguate concurrent datagrams net-timestamp: move timestamp flags out of sk_flags net-timestamp: extend SCM_TIMESTAMPING ancillary data struct cxgb4i : Move stray CPL definitions to cxgb4 driver tcp: reduce spurious retransmits due to transient SACK reneging qlcnic: Initialize dcbnl_ops before register_netdev ...
2014-08-02net: filter: split 'struct sk_filter' into socket and bpf partsAlexei Starovoitov
clean up names related to socket filtering and bpf in the following way: - everything that deals with sockets keeps 'sk_*' prefix - everything that is pure BPF is changed to 'bpf_*' prefix split 'struct sk_filter' into struct sk_filter { atomic_t refcnt; struct rcu_head rcu; struct bpf_prog *prog; }; and struct bpf_prog { u32 jited:1, len:31; struct sock_fprog_kern *orig_prog; unsigned int (*bpf_func)(const struct sk_buff *skb, const struct bpf_insn *filter); union { struct sock_filter insns[0]; struct bpf_insn insnsi[0]; struct work_struct work; }; }; so that 'struct bpf_prog' can be used independent of sockets and cleans up 'unattached' bpf use cases split SK_RUN_FILTER macro into: SK_RUN_FILTER to be used with 'struct sk_filter *' and BPF_PROG_RUN to be used with 'struct bpf_prog *' __sk_filter_release(struct sk_filter *) gains __bpf_prog_release(struct bpf_prog *) helper function also perform related renames for the functions that work with 'struct bpf_prog *', since they're on the same lines: sk_filter_size -> bpf_prog_size sk_filter_select_runtime -> bpf_prog_select_runtime sk_filter_free -> bpf_prog_free sk_unattached_filter_create -> bpf_prog_create sk_unattached_filter_destroy -> bpf_prog_destroy sk_store_orig_filter -> bpf_prog_store_orig_filter sk_release_orig_filter -> bpf_release_orig_filter __sk_migrate_filter -> bpf_migrate_filter __sk_prepare_filter -> bpf_prepare_filter API for attaching classic BPF to a socket stays the same: sk_attach_filter(prog, struct sock *)/sk_detach_filter(struct sock *) and SK_RUN_FILTER(struct sk_filter *, ctx) to execute a program which is used by sockets, tun, af_packet API for 'unattached' BPF programs becomes: bpf_prog_create(struct bpf_prog **)/bpf_prog_destroy(struct bpf_prog *) and BPF_PROG_RUN(struct bpf_prog *, ctx) to execute a program which is used by isdn, ppp, team, seccomp, ptp, xt_bpf, cls_bpf, test_bpf Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>