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>
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>
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 30aba6656f ("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>
-----BEGIN PGP SIGNATURE-----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=8HBN
-----END PGP SIGNATURE-----
Merge tag 'audit-pr-20190702' of 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
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>
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>
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>
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>
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>
V3 namespaced file capabilities were introduced in
commit 8db6c34f1d ("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>
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>
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>
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>
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>
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>
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>
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>
Commit c72051d577 ("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: c72051d577 ("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>
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>
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>
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>
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>
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>
-----BEGIN PGP SIGNATURE-----
iQJIBAABCAAyFiEEcQCq365ubpQNLgrWVeRaWujKfIoFAlrD6T4UHHBhdWxAcGF1
bC1tb29yZS5jb20ACgkQVeRaWujKfIqGOg/9FPgs5cESBrocEOBAqqcmO3qjxaEy
NKQWGTPppZwI5f5pOStL5GT3oU8jQp3IMjzUM2yIElFUg+RM5cwb0bLmhAMCJFCd
vtrJmGDdQ0QEj5wqkprupaVEKENlSKaKePJq3NESFtcHs2cgfcIRsycj1LaOThNi
fUcltiocBDS/jxurCgi2s4O2JTGEXfZaI0GojKjWDddL3N6QcD5aZgPQd/67T0Pt
5dDgkXbGkd5pR97F+LovaTuLTaMXnUx5plMUd/LsueZbOxHjZL2O2E/h4aoXATMX
zKdtG03wEebb65cQyczeTXRIBURIQCka0U0fHx7ZhS8vK2HVgr6oGfsJfyZhSp+l
IIb/T1dSbgUURpMH0DiGs/pQrXO/9o7Rp7wIakycIHD0kcw503hbauqJEc6pwlx6
/WQQTo6GKwHWW67OQ7AbIt4Gh9P/s96s6kEZGRH2NAjKY9xTZVM7+nnKL8hHk0xq
uDN20AZuD5i9cZpVqw+MYdmeuHRuNPglY9S33MyaBbFeWl48voFxiabVpV3ENfLB
Iyc5WzpxekJi9JLneEt6/r6XIissvHxsoIPL1lCYSAPIJQRmqg4sGHKAQ9o5NtFD
MrRZSbBQVwt3+YFKixUcU+nvnhroJsQExejZoFmAdQl8f0TiihwYl8E4lSmy7ntr
IzNm7li+y9VRJ54=
=n1dk
-----END PGP SIGNATURE-----
Merge tag 'audit-pr-20180403' of 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
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>
In commit 45b578fe4c
("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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Commit 2115bb250f ("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>
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.
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
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>
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>
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>
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()
