summaryrefslogtreecommitdiff
path: root/kernel/audit.c
AgeCommit message (Collapse)AuthorFilesLines
2019-12-09audit: Add __rcu annotation to RCU pointerAmol Grover1-2/+3
Add __rcu annotation to RCU-protected global pointer auditd_conn. auditd_conn is an RCU-protected global pointer,i.e., accessed via RCU methods rcu_dereference() and rcu_assign_pointer(), hence it must be annotated with __rcu for sparse to report warnings/errors correctly. Fix multiple instances of the sparse error: error: incompatible types in comparison expression (different address spaces) Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Amol Grover <frextrite@gmail.com> [PM: tweak subject line] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-10-25audit: remove redundant condition check in kauditd_thread()Yunfeng Ye1-2/+2
Warning is found by the code analysis tool: "the condition 'if(ac && rc < 0)' is redundant: ac" The @ac variable has been checked before. It can't be a null pointer here, so remove the redundant condition check. Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-10-03audit: Report suspicious O_CREAT usageKees Cook1-5/+6
This renames the very specific audit_log_link_denied() to audit_log_path_denied() and adds the AUDIT_* type as an argument. This allows for the creation of the new AUDIT_ANOM_CREAT that can be used to report the fifo/regular file creation restrictions that were introduced in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and regular files"). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-07-09Merge tag 'audit-pr-20190702' of ↵Linus Torvalds1-0/+27
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit updates from Paul Moore: "This pull request is a bit early, but with some vacation time coming up I wanted to send this out now just in case the remote Internet Gods decide not to smile on me once the merge window opens. The patchset for v5.3 is pretty minor this time, the highlights include: - When the audit daemon is sent a signal, ensure we deliver information about the sender even when syscall auditing is not enabled/supported. - Add the ability to filter audit records based on network address family. - Tighten the audit field filtering restrictions on string based fields. - Cleanup the audit field filtering verification code. - Remove a few BUG() calls from the audit code" * tag 'audit-pr-20190702' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: remove the BUG() calls in the audit rule comparison functions audit: enforce op for string fields audit: add saddr_fam filter field audit: re-structure audit field valid checks audit: deliver signal_info regarless of syscall
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner1-14/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22audit: deliver signal_info regarless of syscallRichard Guy Briggs1-0/+27
When a process signals the audit daemon (shutdown, rotate, resume, reconfig) but syscall auditing is not enabled, we still want to know the identity of the process sending the signal to the audit daemon. Move audit_signal_info() out of syscall auditing to general auditing but create a new function audit_signal_info_syscall() to take care of the syscall dependent parts for when syscall auditing is enabled. Please see the github kernel audit issue https://github.com/linux-audit/audit-kernel/issues/111 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-21audit: connect LOGIN record to its syscall recordRichard Guy Briggs1-1/+1
Currently the AUDIT_LOGIN event is a standalone record that isn't connected to any other records that may be part of its syscall event. To avoid the confusion of generating two events, connect the records by using its syscall context. Please see the github issue https://github.com/linux-audit/audit-kernel/issues/110 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-02-04audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALLRichard Guy Briggs1-157/+0
Remove audit_context from struct task_struct and struct audit_buffer when CONFIG_AUDIT is enabled but CONFIG_AUDITSYSCALL is not. Also, audit_log_name() (and supporting inode and fcaps functions) should have been put back in auditsc.c when soft and hard link logging was normalized since it is only used by syscall auditing. See github issue https://github.com/linux-audit/audit-kernel/issues/105 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-31audit: ignore fcaps on umountRichard Guy Briggs1-1/+9
Don't fetch fcaps when umount2 is called to avoid a process hang while it waits for the missing resource to (possibly never) re-appear. Note the comment above user_path_mountpoint_at(): * A umount is a special case for path walking. We're not actually interested * in the inode in this situation, and ESTALE errors can be a problem. We * simply want track down the dentry and vfsmount attached at the mountpoint * and avoid revalidating the last component. This can happen on ceph, cifs, 9p, lustre, fuse (gluster) or NFS. Please see the github issue tracker https://github.com/linux-audit/audit-kernel/issues/100 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: merge fuzz in audit_log_fcaps()] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-25audit: add support for fcaps v3Richard Guy Briggs1-2/+4
V3 namespaced file capabilities were introduced in commit 8db6c34f1dbc ("Introduce v3 namespaced file capabilities") Add support for these by adding the "frootid" field to the existing fcaps fields in the NAME and BPRM_FCAPS records. Please see github issue https://github.com/linux-audit/audit-kernel/issues/103 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Acked-by: Serge Hallyn <serge@hallyn.com> [PM: comment tweak to fit an 80 char line width] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-25audit: move loginuid and sessionid from CONFIG_AUDITSYSCALL to CONFIG_AUDITRichard Guy Briggs1-0/+85
loginuid and sessionid (and audit_log_session_info) should be part of CONFIG_AUDIT scope and not CONFIG_AUDITSYSCALL since it is used in CONFIG_CHANGE, ANOM_LINK, FEATURE_CHANGE (and INTEGRITY_RULE), none of which are otherwise dependent on AUDITSYSCALL. Please see github issue https://github.com/linux-audit/audit-kernel/issues/104 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: tweaked subject line for better grep'ing] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-19audit: add syscall information to CONFIG_CHANGE recordsRichard Guy Briggs1-9/+19
Tie syscall information to all CONFIG_CHANGE calls since they are all a result of user actions. Exclude user records from syscall context: Since the function audit_log_common_recv_msg() is shared by a number of AUDIT_CONFIG_CHANGE and the entire range of AUDIT_USER_* record types, and since the AUDIT_CONFIG_CHANGE message type has been converted to a syscall accompanied record type, special-case the AUDIT_USER_* range of messages so they remain standalone records. See: https://github.com/linux-audit/audit-kernel/issues/59 See: https://github.com/linux-audit/audit-kernel/issues/50 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: fix line lengths in kernel/audit.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-15audit: give a clue what CONFIG_CHANGE op was involvedRichard Guy Briggs1-2/+5
The failure to add an audit rule due to audit locked gives no clue what CONFIG_CHANGE operation failed. Similarly the set operation is the only other operation that doesn't give the "op=" field to indicate the action. All other CONFIG_CHANGE records include an op= field to give a clue as to what sort of configuration change is being executed. Since these are the only CONFIG_CHANGE records that that do not have an op= field, add them to bring them in line with the rest. Old records: type=CONFIG_CHANGE msg=audit(1519812997.781:374): pid=610 uid=0 auid=0 ses=1 subj=... audit_enabled=2 res=0 type=CONFIG_CHANGE msg=audit(2018-06-14 14:55:04.507:47) : audit_enabled=1 old=1 auid=unset ses=unset subj=... res=yes New records: type=CONFIG_CHANGE msg=audit(1520958477.855:100): pid=610 uid=0 auid=0 ses=1 subj=... op=add_rule audit_enabled=2 res=0 type=CONFIG_CHANGE msg=audit(2018-06-14 14:55:04.507:47) : op=set audit_enabled=1 old=1 auid=unset ses=unset subj=... res=yes See: https://github.com/linux-audit/audit-kernel/issues/59 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: fixed checkpatch.pl line length problems] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-12-14audit: remove duplicated include from audit.cYueHaibing1-1/+0
Remove duplicated include. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-12-04audit: shorten PATH cap values when zeroRichard Guy Briggs1-4/+6
Since the vast majority of files (99.993% on a typical system) have no fcaps, display "0" instead of the full zero-padded 16 hex digits in the two PATH record cap_f* fields to save netlink bandwidth and disk space. Simply changing the format to %x won't work since the value is two (or possibly more in the future) 32-bit hexadecimal values concatenated and bits in higher order values will be misrepresented. Passes audit-testsuite and userspace tools already work fine. Please see the github issue tracker for more details https://github.com/linux-audit/audit-kernel/issues/101 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Acked-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-27audit: use current whenever possiblePaul Moore1-17/+17
There are many places, notably audit_log_task_info() and audit_log_exit(), that take task_struct pointers but in reality they are always working on the current task. This patch eliminates the task_struct arguments and uses current directly which allows a number of cleanups as well. Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-27audit: minimize our use of audit_log_format()Paul Moore1-6/+5
There are some cases where we are making multiple audit_log_format() calls in a row, for no apparent reason. Squash these down to a single audit_log_format() call whenever possible. Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-19audit: use session_info helperRichard Guy Briggs1-3/+3
There are still a couple of places (mark and watch config changes) that open code auid and ses fields in sequence in records instead of using the audit_log_session_info() helper. Use the helper. Adjust the helper to accommodate being the first fields. Passes audit-testsuite. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: fixed misspellings in the description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-07-17audit: use ktime_get_coarse_real_ts64() for timestampsPaul Moore1-1/+1
Commit c72051d5778a ("audit: use ktime_get_coarse_ts64() for time access") converted audit's use of current_kernel_time64() to the new ktime_get_coarse_ts64() function. Unfortunately this resulted in incorrect timestamps, e.g. events stamped with the year 1969 despite it being 2018. This patch corrects this by using ktime_get_coarse_real_ts64() just like the current_kernel_time64() wrapper. Fixes: c72051d5778a ("audit: use ktime_get_coarse_ts64() for time access") Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-07-03audit: use ktime_get_coarse_ts64() for time accessArnd Bergmann1-1/+1
The API got renamed for consistency with the other time accessors, this changes the audit caller as well. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-06-19audit: eliminate audit_enabled magic number comparisonRichard Guy Briggs1-3/+0
Remove comparison of audit_enabled to magic numbers outside of audit. Related: https://github.com/linux-audit/audit-kernel/issues/86 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-06-19audit: rename FILTER_TYPE to FILTER_EXCLUDERichard Guy Briggs1-1/+1
The AUDIT_FILTER_TYPE name is vague and misleading due to not describing where or when the filter is applied and obsolete due to its available filter fields having been expanded. Userspace has already renamed it from AUDIT_FILTER_TYPE to AUDIT_FILTER_EXCLUDE without checking if it already exists. The userspace maintainer assures that as long as it is set to the same value it will not be a problem since the userspace code does not treat compiler warnings as errors. If this policy changes then checks if it already exists can be added at the same time. See: https://github.com/linux-audit/audit-kernel/issues/89 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-05-15audit: use inline function to get audit contextRichard Guy Briggs1-4/+2
Recognizing that the audit context is an internal audit value, use an access function to retrieve the audit context pointer for the task rather than reaching directly into the task struct to get it. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: merge fuzz in auditsc.c and selinuxfs.c, checkpatch.pl fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-04-20audit: add syscall information to FEATURE_CHANGE recordsRichard Guy Briggs1-2/+2
Tie syscall information to FEATURE_CHANGE calls since it is a result of user action. See: https://github.com/linux-audit/audit-kernel/issues/80 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: 80-char fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-04-07Merge tag 'audit-pr-20180403' of ↵Linus Torvalds1-32/+76
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit updates from Paul Moore: "We didn't have anything to send for v4.16, but we're back with a little more than usual for v4.17. Eleven patches in total, most fall into the small fix category, but there are three non-trivial changes worth calling out: - the audit entry filter is being removed after deprecating it for quite a while (years of no one really using it because it turns out to be not very practical) - created our own version of "__mutex_owner()" because the locking folks were upset we were using theirs - improved our handling of kernel command line parameters to make them more forgiving - we fixed auditing of symlink operations Everything passes the audit-testsuite and as of a few minutes ago it merges well with your tree" * tag 'audit-pr-20180403' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: add refused symlink to audit_names audit: remove path param from link denied function audit: link denied should not directly generate PATH record audit: make ANOM_LINK obey audit_enabled and audit_dummy_context audit: do not panic on invalid boot parameter audit: track the owner of the command mutex ourselves audit: return on memory error to avoid null pointer dereference audit: bail before bug check if audit disabled audit: deprecate the AUDIT_FILTER_ENTRY filter audit: session ID should not set arch quick field pointer audit: update bugtracker and source URIs
2018-03-26treewide: Align function definition open/close bracesJoe Perches1-3/+3
Some functions definitions have either the initial open brace and/or the closing brace outside of column 1. Move those braces to column 1. This allows various function analyzers like gnu complexity to work properly for these modified functions. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-03-21audit: remove path param from link denied functionRichard Guy Briggs1-2/+1
In commit 45b578fe4c3cade6f4ca1fc934ce199afd857edc ("audit: link denied should not directly generate PATH record") the need for the struct path *link parameter was removed. Remove the now useless struct path argument. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-09audit: link denied should not directly generate PATH recordRichard Guy Briggs1-13/+1
Audit link denied events generate duplicate PATH records which disagree in different ways from symlink and hardlink denials. audit_log_link_denied() should not directly generate PATH records. See: https://github.com/linux-audit/audit-kernel/issues/21 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-09audit: make ANOM_LINK obey audit_enabled and audit_dummy_contextRichard Guy Briggs1-0/+3
Audit link denied events emit disjointed records when audit is disabled. No records should be emitted when audit is disabled. See: https://github.com/linux-audit/audit-kernel/issues/21 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-06audit: do not panic on invalid boot parameterGreg Edwards1-7/+14
If you pass in an invalid audit boot parameter value, e.g. "audit=off", the kernel panics very early in boot before the regular console is initialized. Unless you have earlyprintk enabled, there is no indication of what the problem is on the console. Convert the panic() calls to pr_err(), and leave auditing enabled if an invalid parameter value was passed in. Modify the parameter to also accept "on" or "off" as valid values, and update the documentation accordingly. Signed-off-by: Greg Edwards <gedwards@ddn.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-02-23audit: track the owner of the command mutex ourselvesPaul Moore1-11/+55
Evidently the __mutex_owner() function was never intended for use outside the core mutex code, so build a thing locking wrapper around the mutex code which allows us to track the mutex owner. One, arguably positive, side effect is that this allows us to hide the audit_cmd_mutex inside of kernel/audit.c behind the lock/unlock functions. Reported-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-02-22audit: return on memory error to avoid null pointer dereferenceRichard Guy Briggs1-0/+2
If there is a memory allocation error when trying to change an audit kernel feature value, the ignored allocation error will trigger a NULL pointer dereference oops on subsequent use of that pointer. Return instead. Passes audit-testsuite. See: https://github.com/linux-audit/audit-kernel/issues/76 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: not necessary (other funcs check for NULL), but a good practice] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-02-14audit: update bugtracker and source URIsRichard Guy Briggs1-1/+2
Since the Linux Audit project has transitioned completely over to github, update the MAINTAINERS file and the primary audit source file to reflect that reality. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-11Audit: remove unused audit_log_secctx functionCasey Schaufler1-26/+0
The function audit_log_secctx() is unused in the upstream kernel. All it does is wrap another function that doesn't need wrapping. It claims to give you the SELinux context, but that is not true if you are using a different security module. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-11audit: Allow auditd to set pid to 0 to end auditingSteve Grubb1-13/+16
The API to end auditing has historically been for auditd to set the pid to 0. This patch restores that functionality. See: https://github.com/linux-audit/audit-kernel/issues/69 Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-11audit: use audit_set_enabled() in audit_enable()Paul Moore1-2/+2
Use audit_set_enabled() to enable auditing during early boot. This obviously won't emit an audit change record, but it will work anyway and should help prevent in future problems by consolidating the enable/disable code in one function. Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-11audit: convert audit_ever_enabled to a booleanPaul Moore1-1/+1
We were treating it as a boolean, let's make it a boolean to help avoid future mistakes. Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-11audit: don't use simple_strtol() anymorePaul Moore1-2/+7
The simple_strtol() function is deprecated, use kstrtol() instead. Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-11audit: initialize the audit subsystem as early as possiblePaul Moore1-1/+1
We can't initialize the audit subsystem until after the network layer is initialized (core_initcall), but do it soon after. Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-11audit: ensure that 'audit=1' actually enables audit for PID 1Paul Moore1-5/+5
Prior to this patch we enabled audit in audit_init(), which is too late for PID 1 as the standard initcalls are run after the PID 1 task is forked. This means that we never allocate an audit_context (see audit_alloc()) for PID 1 and therefore miss a lot of audit events generated by PID 1. This patch enables audit as early as possible to help ensure that when PID 1 is forked it can allocate an audit_context if required. Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-09-05audit: update the function commentsGeliang Tang1-1/+1
Update the function comments to match the code. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-09-05audit: Reduce overhead using a coarse clockMel Gorman1-1/+1
Commit 2115bb250f26 ("audit: Use timespec64 to represent audit timestamps") noted that audit timestamps were not y2038 safe and used a 64-bit timestamp. In itself, this makes sense but the conversion was from CURRENT_TIME to ktime_get_real_ts64() which is a heavier call to record an accurate timestamp which is required in some, but not all, cases. The impact is that when auditd is running without any rules that all syscalls have higher overhead. This is visible in the sysbench-thread benchmark as a 11.5% performance hit. That benchmark is dumb as rocks but it's also visible in redis as an 8-10% hit on all operations which is of greater concern. It is somewhat stupid of audit to track syscalls without any rules related to syscalls but that is how it behaves. The overhead can be directly measured with perf comparing 4.9 with 4.12 4.9 7.76% sysbench [kernel.vmlinux] [k] __schedule 7.62% sysbench [kernel.vmlinux] [k] _raw_spin_lock 7.37% sysbench libpthread-2.22.so [.] __lll_lock_elision 7.29% sysbench [kernel.vmlinux] [.] syscall_return_via_sysret 6.59% sysbench [kernel.vmlinux] [k] native_sched_clock 5.21% sysbench libc-2.22.so [.] __sched_yield 4.38% sysbench [kernel.vmlinux] [k] entry_SYSCALL_64 4.28% sysbench [kernel.vmlinux] [k] do_syscall_64 3.49% sysbench libpthread-2.22.so [.] __lll_unlock_elision 3.13% sysbench [kernel.vmlinux] [k] __audit_syscall_exit 2.87% sysbench [kernel.vmlinux] [k] update_curr 2.73% sysbench [kernel.vmlinux] [k] pick_next_task_fair 2.31% sysbench [kernel.vmlinux] [k] syscall_trace_enter 2.20% sysbench [kernel.vmlinux] [k] __audit_syscall_entry ..... 0.00% swapper [kernel.vmlinux] [k] read_tsc 4.12 7.84% sysbench [kernel.vmlinux] [k] __schedule 7.05% sysbench [kernel.vmlinux] [k] _raw_spin_lock 6.57% sysbench libpthread-2.22.so [.] __lll_lock_elision 6.50% sysbench [kernel.vmlinux] [.] syscall_return_via_sysret 5.95% sysbench [kernel.vmlinux] [k] read_tsc 5.71% sysbench [kernel.vmlinux] [k] native_sched_clock 4.78% sysbench libc-2.22.so [.] __sched_yield 4.30% sysbench [kernel.vmlinux] [k] entry_SYSCALL_64 3.94% sysbench [kernel.vmlinux] [k] do_syscall_64 3.37% sysbench libpthread-2.22.so [.] __lll_unlock_elision 3.32% sysbench [kernel.vmlinux] [k] __audit_syscall_exit 2.91% sysbench [kernel.vmlinux] [k] __getnstimeofday64 Note the additional overhead from read_tsc which goes from 0% to 5.95%. This is on a single-socket E3-1230 but similar overheads have been measured on an older machine which the patch also eliminates. The patch in question has no explanation as to why a fully-accurate timestamp is required and is likely an oversight. Using a coarser, but monotically increasing, timestamp the overhead can be eliminated. While it can be worked around by configuring or disabling audit, it's tricky enough to detect that a kernel fix is justified. With this patch, we see the following; sysbenchthread 4.9.0 4.12.0 4.12.0 vanilla vanilla coarse-v1r1 Amean 1 1.49 ( 0.00%) 1.66 ( -11.42%) 1.51 ( -1.34%) Amean 3 1.48 ( 0.00%) 1.65 ( -11.45%) 1.50 ( -0.96%) Amean 5 1.49 ( 0.00%) 1.67 ( -12.31%) 1.51 ( -1.83%) Amean 7 1.49 ( 0.00%) 1.66 ( -11.72%) 1.50 ( -0.67%) Amean 12 1.48 ( 0.00%) 1.65 ( -11.57%) 1.52 ( -2.89%) Amean 16 1.49 ( 0.00%) 1.65 ( -11.13%) 1.51 ( -1.73%) The benchmark is reporting the time required for different thread counts to lock/unlock a private mutex which, while dense, demonstrates the syscall overhead. This is showing that 4.12 took a 11-12% hit but the overhead is almost eliminated by the patch. While the variance is not reported here, it's well within the noise with the patch applied. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-07-20Merge branch 'stable-4.13' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds1-0/+1
Pull audit fix from Paul Moore: "A small audit fix, just a single line, to plug a memory leak in some audit error handling code" * 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit: audit: fix memleak in auditd_send_unicast_skb.
2017-07-19audit: fix memleak in auditd_send_unicast_skb.Shu Wang1-0/+1
Found this issue by kmemleak report, auditd_send_unicast_skb did not free skb if rcu_dereference(auditd_conn) returns null. unreferenced object 0xffff88082568ce00 (size 256): comm "auditd", pid 1119, jiffies 4294708499 backtrace: [<ffffffff8176166a>] kmemleak_alloc+0x4a/0xa0 [<ffffffff8121820c>] kmem_cache_alloc_node+0xcc/0x210 [<ffffffff8161b99d>] __alloc_skb+0x5d/0x290 [<ffffffff8113c614>] audit_make_reply+0x54/0xd0 [<ffffffff8113dfa7>] audit_receive_msg+0x967/0xd70 ---------------- (gdb) list *audit_receive_msg+0x967 0xffffffff8113dff7 is in audit_receive_msg (kernel/audit.c:1133). 1132 skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr)); --------------- [<ffffffff8113e402>] audit_receive+0x52/0xa0 [<ffffffff8166c561>] netlink_unicast+0x181/0x240 [<ffffffff8166c8e2>] netlink_sendmsg+0x2c2/0x3b0 [<ffffffff816112e8>] sock_sendmsg+0x38/0x50 [<ffffffff816117a2>] SYSC_sendto+0x102/0x190 [<ffffffff81612f4e>] SyS_sendto+0xe/0x10 [<ffffffff8176d337>] entry_SYSCALL_64_fastpath+0x1a/0xa5 [<ffffffffffffffff>] 0xffffffffffffffff Signed-off-by: Shu Wang <shuwang@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-07-05Merge branch 'stable-4.13' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds1-32/+29
Pull audit updates from Paul Moore: "Things are relatively quiet on the audit front for v4.13, just five patches for a total diffstat of 102 lines. There are two patches from Richard to consistently record the POSIX capabilities and add the ambient capability information as well. I also chipped in two patches to fix a race condition with the auditd tracking code and ensure we don't skip sending any records to the audit multicast group. Finally a single style fix that I accepted because I must have been in a good mood that day. Everything passes our test suite, and should be relatively harmless, please merge for v4.13" * 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit: audit: make sure we never skip the multicast broadcast audit: fix a race condition with the auditd tracking code audit: style fix audit: add ambient capabilities to CAPSET and BPRM_FCAPS records audit: unswing cap_* fields in PATH records
2017-06-16audit: make sure we never skip the multicast broadcastPaul Moore1-3/+2
When the auditd connection is reset, either intentionally or due to a failure, any records that were in the main backlog queue would not be sent in a multicast broadcast. This patch fixes this problem by not flushing the main backlog queue on a connection reset, the main kauditd_thread() will take care of that normally. Resolves: https://github.com/linux-audit/audit-kernel/issues/41 Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-06-13audit: fix a race condition with the auditd tracking codePaul Moore1-13/+23
Originally reported by Adam and Dusty, it appears we have a small race window in kauditd_thread(), as documented in the Fedora BZ: * https://bugzilla.redhat.com/show_bug.cgi?id=1459326#c35 "This issue is partly due to the read-copy nature of RCU, and partly due to how we sync the auditd_connection state across kauditd_thread and the audit control channel. The kauditd_thread thread is always running so it can service the record queues and emit the multicast messages, if it happens to be just past the "main_queue" label, but before the "if (sk == NULL || ...)" if-statement which calls auditd_reset() when the new auditd connection is registered it could end up resetting the auditd connection, regardless of if it is valid or not. This is a rather small window and the variable nature of multi-core scheduling explains why this is proving rather difficult to reproduce." The fix is to have functions only call auditd_reset() when they believe that the kernel/auditd connection is still valid, e.g. non-NULL, and to have these callers pass their local copy of the auditd_connection pointer to auditd_reset() where it can be compared with the current connection state before resetting. If the caller has a stale state tracking pointer then the reset is ignored. We also make a small change to kauditd_thread() so that if the kernel/auditd connection is dead we skip the retry queue and send the records straight to the hold queue. This is necessary as we used to rely on auditd_reset() to occasionally purge the retry queue but we are going to be calling the reset function much less now and we want to make sure the retry queue doesn't grow unbounded. Reported-by: Adam Williamson <awilliam@redhat.com> Reported-by: Dusty Mabe <dustymabe@redhat.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23audit: unswing cap_* fields in PATH recordsRichard Guy Briggs1-16/+4
The cap_* fields swing in and out of PATH records. If no capabilities are set, the cap_* fields are completely missing and when one of the cap_fi or cap_fp values is empty, that field is omitted. Original: type=PATH msg=audit(04/20/2017 12:17:11.222:193) : item=1 name=/lib64/ld-linux-x86-64.so.2 inode=787694 dev=08:03 mode=file,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:ld_so_t:s0 nametype=NORMAL type=PATH msg=audit(04/20/2017 12:17:11.222:193) : item=0 name=/home/sleep inode=1319469 dev=08:03 mode=file,suid,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:bin_t:s0 nametype=NORMAL cap_fp=sys_admin cap_fe=1 cap_fver=2 Normalize the PATH record by always printing all 4 cap_* fields. Fixed: type=PATH msg=audit(04/20/2017 13:01:31.679:201) : item=1 name=/lib64/ld-linux-x86-64.so.2 inode=787694 dev=08:03 mode=file,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:ld_so_t:s0 nametype=NORMAL cap_fp=none cap_fi=none cap_fe=0 cap_fver=0 type=PATH msg=audit(04/20/2017 13:01:31.679:201) : item=0 name=/home/sleep inode=1319469 dev=08:03 mode=file,suid,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:bin_t:s0 nametype=NORMAL cap_fp=sys_admin cap_fi=none cap_fe=1 cap_fver=2 See: https://github.com/linux-audit/audit-kernel/issues/42 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-03Merge branch 'stable-4.12' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds1-146/+173
Pull audit updates from Paul Moore: "Fourteen audit patches for v4.12 that span the full range of fixes, new features, and internal cleanups. We have a patches to move to 64-bit timestamps, convert refcounts from atomic_t to refcount_t, track PIDs using the pid struct instead of pid_t, convert our own private audit buffer cache to a standard kmem_cache, log kernel module names when they are unloaded, and normalize the NETFILTER_PKT to make the userspace folks happier. From a fixes perspective, the most important is likely the auditd connection tracking RCU fix; it was a rather brain dead bug that I'll take the blame for, but thankfully it didn't seem to affect many people (only one report). I think the patch subject lines and commit descriptions do a pretty good job of explaining the details and why the changes are important so I'll point you there instead of duplicating it here; as usual, if you have any questions you know where to find us. We also manage to take out more code than we put in this time, that always makes me happy :)" * 'stable-4.12' of git://git.infradead.org/users/pcmoore/audit: audit: fix the RCU locking for the auditd_connection structure audit: use kmem_cache to manage the audit_buffer cache audit: Use timespec64 to represent audit timestamps audit: store the auditd PID as a pid struct instead of pid_t audit: kernel generated netlink traffic should have a portid of 0 audit: combine audit_receive() and audit_receive_skb() audit: convert audit_watch.count from atomic_t to refcount_t audit: convert audit_tree.count from atomic_t to refcount_t audit: normalize NETFILTER_PKT netfilter: use consistent ipv4 network offset in xt_AUDIT audit: log module name on delete_module audit: remove unnecessary semicolon in audit_watch_handle_event() audit: remove unnecessary semicolon in audit_mark_handle_event() audit: remove unnecessary semicolon in audit_field_valid()
2017-05-02audit: fix the RCU locking for the auditd_connection structurePaul Moore1-57/+100
Cong Wang correctly pointed out that the RCU read locking of the auditd_connection struct was wrong, this patch correct this by adopting a more traditional, and correct RCU locking model. This patch is heavily based on an earlier prototype by Cong Wang. Cc: <stable@vger.kernel.org> # 4.11.x- Reported-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>