Commit Graph

350 Commits

Author SHA1 Message Date
Geliang Tang 196a508559 audit: update the function comments
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>
2017-09-05 09:46:59 -04:00
Mel Gorman e832bf48c8 audit: Reduce overhead using a coarse clock
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>
2017-09-05 09:46:54 -04:00
Linus Torvalds 7391786a64 Merge branch 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit
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
2017-07-05 11:24:05 -07:00
Richard Guy Briggs 7786f6b6df audit: add ambient capabilities to CAPSET and BPRM_FCAPS records
Capabilities were augmented to include ambient capabilities in v4.3
commit 58319057b7 ("capabilities: ambient capabilities").

Add ambient capabilities to the audit BPRM_FCAPS and CAPSET records.

The record contains fields "old_pp", "old_pi", "old_pe", "new_pp",
"new_pi", "new_pe" so in keeping with the previous record
normalizations, change the "new_*" variants to simply drop the "new_"
prefix.

A sample of the replaced BPRM_FCAPS record:
RAW: type=BPRM_FCAPS msg=audit(1491468034.252:237): fver=2
fp=0000000000200000 fi=0000000000000000 fe=1 old_pp=0000000000000000
old_pi=0000000000000000 old_pe=0000000000000000 old_pa=0000000000000000
pp=0000000000200000 pi=0000000000000000 pe=0000000000200000
pa=0000000000000000

INTERPRET: type=BPRM_FCAPS msg=audit(04/06/2017 04:40:34.252:237):
fver=2 fp=sys_admin fi=none fe=chown old_pp=none old_pi=none
old_pe=none old_pa=none pp=sys_admin pi=none pe=sys_admin pa=none

A sample of the replaced CAPSET record:
RAW: type=CAPSET msg=audit(1491469502.371:242): pid=833
cap_pi=0000003fffffffff cap_pp=0000003fffffffff cap_pe=0000003fffffffff
cap_pa=0000000000000000

INTERPRET: type=CAPSET msg=audit(04/06/2017 05:05:02.371:242) : pid=833
cap_pi=chown,dac_override,dac_read_search,fowner,fsetid,kill,
setgid,setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,sys_time,
sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pp=chown,dac_override,dac_read_search,fowner,fsetid,kill,setgid,
setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,
sys_time,sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pe=chown,dac_override,dac_read_search,fowner,fsetid,kill,setgid,
setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,
sys_time,sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pa=none

See: https://github.com/linux-audit/audit-kernel/issues/40

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-30 17:36:11 -04:00
Linus Torvalds 5133cd7518 Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify updates from Jan Kara:
 "The branch contains mainly a rework of fsnotify infrastructure fixing
  a shortcoming that we have waited for response to fanotify permission
  events with SRCU read lock held and when the process consuming events
  was slow to respond the kernel has stalled.

  It also contains several cleanups of unnecessary indirections in
  fsnotify framework and a bugfix from Amir fixing leakage of kernel
  internal errno to userspace"

* 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (37 commits)
  fanotify: don't expose EOPENSTALE to userspace
  fsnotify: remove a stray unlock
  fsnotify: Move ->free_mark callback to fsnotify_ops
  fsnotify: Add group pointer in fsnotify_init_mark()
  fsnotify: Drop inode_mark.c
  fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark()
  fsnotify: Remove fsnotify_detach_group_marks()
  fsnotify: Rename fsnotify_clear_marks_by_group_flags()
  fsnotify: Inline fsnotify_clear_{inode|vfsmount}_mark_group()
  fsnotify: Remove fsnotify_recalc_{inode|vfsmount}_mask()
  fsnotify: Remove fsnotify_set_mark_{,ignored_}mask_locked()
  fanotify: Release SRCU lock when waiting for userspace response
  fsnotify: Pass fsnotify_iter_info into handle_event handler
  fsnotify: Provide framework for dropping SRCU lock in ->handle_event
  fsnotify: Remove special handling of mark destruction on group shutdown
  fsnotify: Detach mark from object list when last reference is dropped
  fsnotify: Move queueing of mark for destruction into fsnotify_put_mark()
  inotify: Do not drop mark reference under idr_lock
  fsnotify: Free fsnotify_mark_connector when there is no mark attached
  fsnotify: Lock object list with connector lock
  ...
2017-05-03 11:05:15 -07:00
Deepa Dinamani 2115bb250f audit: Use timespec64 to represent audit timestamps
struct timespec is not y2038 safe.
Audit timestamps are recorded in string format into
an audit buffer for a given context.
These mark the entry timestamps for the syscalls.
Use y2038 safe struct timespec64 to represent the times.
The log strings can handle this transition as strings can
hold upto 1024 characters.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-02 10:16:05 -04:00
Jan Kara 08991e83b7 fsnotify: Free fsnotify_mark_connector when there is no mark attached
Currently we free fsnotify_mark_connector structure only when inode /
vfsmount is getting freed. This can however impose noticeable memory
overhead when marks get attached to inodes only temporarily. So free the
connector structure once the last mark is detached from the object.
Since notification infrastructure can be working with the connector
under the protection of fsnotify_mark_srcu, we have to be careful and
free the fsnotify_mark_connector only after SRCU period passes.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:35 +02:00
Jan Kara 9dd813c15b fsnotify: Move mark list head from object into dedicated structure
Currently notification marks are attached to object (inode or vfsmnt) by
a hlist_head in the object. The list is also protected by a spinlock in
the object. So while there is any mark attached to the list of marks,
the object must be pinned in memory (and thus e.g. last iput() deleting
inode cannot happen). Also for list iteration in fsnotify() to work, we
must hold fsnotify_mark_srcu lock so that mark itself and
mark->obj_list.next cannot get freed. Thus we are required to wait for
response to fanotify events from userspace process with
fsnotify_mark_srcu lock held. That causes issues when userspace process
is buggy and does not reply to some event - basically the whole
notification subsystem gets eventually stuck.

So to be able to drop fsnotify_mark_srcu lock while waiting for
response, we have to pin the mark in memory and make sure it stays in
the object list (as removing the mark waiting for response could lead to
lost notification events for groups later in the list). However we don't
want inode reclaim to block on such mark as that would lead to system
just locking up elsewhere.

This commit is the first in the series that paves way towards solving
these conflicting lifetime needs. Instead of anchoring the list of marks
directly in the object, we anchor it in a dedicated structure
(fsnotify_mark_connector) and just point to that structure from the
object. The following commits will also add spinlock protecting the list
and object pointer to the structure.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:34 +02:00
Paul Moore ab6434a137 audit: move audit_signal_info() into kernel/auditsc.c
Commit 5b52330bbf ("audit: fix auditd/kernel connection state
tracking") made inlining audit_signal_info() a bit pointless as
it was always calling into auditd_test_task() so let's remove the
inline function in kernel/audit.h and convert __audit_signal_info()
in kernel/auditsc.c into audit_signal_info().

Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-27 14:30:06 -04:00
Paul Moore 5b52330bbf audit: fix auditd/kernel connection state tracking
What started as a rather straightforward race condition reported by
Dmitry using the syzkaller fuzzer ended up revealing some major
problems with how the audit subsystem managed its netlink sockets and
its connection with the userspace audit daemon.  Fixing this properly
had quite the cascading effect and what we are left with is this rather
large and complicated patch.  My initial goal was to try and decompose
this patch into multiple smaller patches, but the way these changes
are intertwined makes it difficult to split these changes into
meaningful pieces that don't break or somehow make things worse for
the intermediate states.

The patch makes a number of changes, but the most significant are
highlighted below:

* The auditd tracking variables, e.g. audit_sock, are now gone and
replaced by a RCU/spin_lock protected variable auditd_conn which is
a structure containing all of the auditd tracking information.

* We no longer track the auditd sock directly, instead we track it
via the network namespace in which it resides and we use the audit
socket associated with that namespace.  In spirit, this is what the
code was trying to do prior to this patch (at least I think that is
what the original authors intended), but it was done rather poorly
and added a layer of obfuscation that only masked the underlying
problems.

* Big backlog queue cleanup, again.  In v4.10 we made some pretty big
changes to how the audit backlog queues work, here we haven't changed
the queue design so much as cleaned up the implementation.  Brought
about by the locking changes, we've simplified kauditd_thread() quite
a bit by consolidating the queue handling into a new helper function,
kauditd_send_queue(), which allows us to eliminate a lot of very
similar code and makes the looping logic in kauditd_thread() clearer.

* All netlink messages sent to auditd are now sent via
auditd_send_unicast_skb().  Other than just making sense, this makes
the lock handling easier.

* Change the audit_log_start() sleep behavior so that we never sleep
on auditd events (unchanged) or if the caller is holding the
audit_cmd_mutex (changed).  Previously we didn't sleep if the caller
was auditd or if the message type fell between a certain range; the
type check was a poor effort of doing what the cmd_mutex check now
does.  Richard Guy Briggs originally proposed not sleeping the
cmd_mutex owner several years ago but his patch wasn't acceptable
at the time.  At least the idea lives on here.

* A problem with the lost record counter has been resolved.  Steve
Grubb and I both happened to notice this problem and according to
some quick testing by Steve, this problem goes back quite some time.
It's largely a harmless problem, although it may have left some
careful sysadmins quite puzzled.

Cc: <stable@vger.kernel.org> # 4.10.x-
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-21 11:26:35 -04:00
Linus Torvalds b8989bccd6 Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "The audit changes for v4.11 are relatively small compared to what we
  did for v4.10, both in terms of size and impact.

   - two patches from Steve tweak the formatting for some of the audit
     records to make them more consistent with other audit records.

   - three patches from Richard record the name of a module on module
     load, fix the logging of sockaddr information when using
     socketcall() on 32-bit systems, and add the ability to reset
     audit's lost record counter.

   - my lone patch just fixes an annoying style nit that I was reminded
     about by one of Richard's patches.

  All these patches pass our test suite"

* 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit:
  audit: remove unnecessary curly braces from switch/case statements
  audit: log module name on init_module
  audit: log 32-bit socketcalls
  audit: add feature audit_lost reset
  audit: Make AUDIT_ANOM_ABEND event normalized
  audit: Make AUDIT_KERNEL event conform to the specification
2017-02-21 13:25:50 -08:00
Paul Moore fe8e52b9b9 audit: remove unnecessary curly braces from switch/case statements
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-02-14 13:32:12 -05:00
Richard Guy Briggs ca86cad738 audit: log module name on init_module
This adds a new auxiliary record MODULE_INIT to the SYSCALL event.

We get finit_module for free since it made most sense to hook this in to
load_module().

https://github.com/linux-audit/audit-kernel/issues/7
https://github.com/linux-audit/audit-kernel/wiki/RFE-Module-Load-Record-Format

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
[PM: corrected links in the commit description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-02-13 16:17:13 -05:00
Linus Torvalds dcdaa2f948 Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "After the small number of patches for v4.9, we've got a much bigger
  pile for v4.10.

  The bulk of these patches involve a rework of the audit backlog queue
  to enable us to move the netlink multicasting out of the task/thread
  that generates the audit record and into the kernel thread that emits
  the record (just like we do for the audit unicast to auditd).

  While we were playing with the backlog queue(s) we fixed a number of
  other little problems with the code, and from all the testing so far
  things look to be in much better shape now. Doing this also allowed us
  to re-enable disabling IRQs for some netns operations ("netns: avoid
  disabling irq for netns id").

  The remaining patches fix some small problems that are well documented
  in the commit descriptions, as well as adding session ID filtering
  support"

* 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit:
  audit: use proper refcount locking on audit_sock
  netns: avoid disabling irq for netns id
  audit: don't ever sleep on a command record/message
  audit: handle a clean auditd shutdown with grace
  audit: wake up kauditd_thread after auditd registers
  audit: rework audit_log_start()
  audit: rework the audit queue handling
  audit: rename the queues and kauditd related functions
  audit: queue netlink multicast sends just like we do for unicast sends
  audit: fixup audit_init()
  audit: move kaudit thread start from auditd registration to kaudit init (#2)
  audit: add support for session ID user filter
  audit: fix formatting of AUDIT_CONFIG_CHANGE events
  audit: skip sessionid sentinel value when auto-incrementing
  audit: tame initialization warning len_abuf in audit_log_execve_info
  audit: less stack usage for /proc/*/loginuid
2016-12-14 14:06:40 -08:00
Steve Grubb 89670affa2 audit: Make AUDIT_ANOM_ABEND event normalized
The audit event specification asks for certain fields to exist in
all events. Running 'ausearch -m anom_abend -sv yes' returns no
events. This patch adds the result field so that the
AUDIT_ANOM_ABEND event conforms to the rules.

Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-14 16:00:13 -05:00
Richard Guy Briggs 8fae477056 audit: add support for session ID user filter
Define AUDIT_SESSIONID in the uapi and add support for specifying user
filters based on the session ID.  Also add the new session ID filter
to the feature bitmap so userspace knows it is available.

https://github.com/linux-audit/audit-kernel/issues/4
RFE: add a session ID filter to the kernel's user filter

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: combine multiple patches from Richard into this one]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-11-29 15:10:12 -05:00
Richard Guy Briggs 833fc48d18 audit: skip sessionid sentinel value when auto-incrementing
The value (unsigned int)-1 is used as a sentinel to indicate the
sessionID is unset.  Skip this value when the session_id value wraps.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-11-20 15:28:22 -05:00
Richard Guy Briggs 8443075eac audit: tame initialization warning len_abuf in audit_log_execve_info
Tame initialization warning of len_abuf in audit_log_execve_info even
though there isn't presently a bug introduced by commit 43761473c2
("audit: fix a double fetch in audit_log_single_execve_arg()").  Using
UNINITIALIZED_VAR instead may mask future bugs.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-11-14 15:18:48 -05:00
Linus Torvalds 3cd013ab79 Merge branch 'stable-4.9' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "Another relatively small pull request for v4.9 with just two patches.

  The patch from Richard updates the list of features we support and
  report back to userspace; this should have been sent earlier with the
  rest of the v4.8 patches but it got lost in my inbox.

  The second patch fixes a problem reported by our Android friends where
  we weren't very consistent in recording PIDs"

* 'stable-4.9' of git://git.infradead.org/users/pcmoore/audit:
  audit: add exclude filter extension to feature bitmap
  audit: consistently record PIDs with task_tgid_nr()
2016-10-04 14:21:41 -07:00
Paul Moore fa2bea2f5c audit: consistently record PIDs with task_tgid_nr()
Unfortunately we record PIDs in audit records using a variety of
methods despite the correct way being the use of task_tgid_nr().
This patch converts all of these callers, except for the case of
AUDIT_SET in audit_receive_msg() (see the comment in the code).

Reported-by: Jeff Vander Stoep <jeffv@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-08-30 17:19:13 -04:00
Linus Torvalds 797cee982e Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "Six audit patches for 4.8.

  There are a couple of style and minor whitespace tweaks for the logs,
  as well as a minor fixup to catch errors on user filter rules, however
  the major improvements are a fix to the s390 syscall argument masking
  code (reviewed by the nice s390 folks), some consolidation around the
  exclude filtering (less code, always a win), and a double-fetch fix
  for recording the execve arguments"

* 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit:
  audit: fix a double fetch in audit_log_single_execve_arg()
  audit: fix whitespace in CWD record
  audit: add fields to exclude filter by reusing user filter
  s390: ensure that syscall arguments are properly masked on s390
  audit: fix some horrible switch statement style crimes
  audit: fixup: log on errors from filter user rules
2016-07-29 17:54:17 -07:00
Paul Moore 43761473c2 audit: fix a double fetch in audit_log_single_execve_arg()
There is a double fetch problem in audit_log_single_execve_arg()
where we first check the execve(2) argumnets for any "bad" characters
which would require hex encoding and then re-fetch the arguments for
logging in the audit record[1].  Of course this leaves a window of
opportunity for an unsavory application to munge with the data.

This patch reworks things by only fetching the argument data once[2]
into a buffer where it is scanned and logged into the audit
records(s).  In addition to fixing the double fetch, this patch
improves on the original code in a few other ways: better handling
of large arguments which require encoding, stricter record length
checking, and some performance improvements (completely unverified,
but we got rid of some strlen() calls, that's got to be a good
thing).

As part of the development of this patch, I've also created a basic
regression test for the audit-testsuite, the test can be tracked on
GitHub at the following link:

 * https://github.com/linux-audit/audit-testsuite/issues/25

[1] If you pay careful attention, there is actually a triple fetch
problem due to a strnlen_user() call at the top of the function.

[2] This is a tiny white lie, we do make a call to strnlen_user()
prior to fetching the argument data.  I don't like it, but due to the
way the audit record is structured we really have no choice unless we
copy the entire argument at once (which would require a rather
wasteful allocation).  The good news is that with this patch the
kernel no longer relies on this strnlen_user() value for anything
beyond recording it in the log, we also update it with a trustworthy
value whenever possible.

Reported-by: Pengfei Wang <wpengfeinudt@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-07-20 14:15:46 -04:00
Steve Grubb 0b7a0fdb29 audit: fix whitespace in CWD record
Fix the whitespace in the CWD record

Signed-off-by: Steve Grubb <sgrubb@redhat.com>
[PM: fixed subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-07-14 17:47:43 -04:00
Linus Torvalds 89a82a9218 Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore:
 "Two small patches to fix audit problems in 4.7-rcX: the first fixes a
  potential kref leak, the second removes some header file noise.

  The first is an important bug fix that really should go in before 4.7
  is released, the second is not critical, but falls into the very-nice-
  to-have category so I'm including in the pull request.

  Both patches are straightforward, self-contained, and pass our
  testsuite without problem"

* 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit:
  audit: move audit_get_tty to reduce scope and kabi changes
  audit: move calcs after alloc and check when logging set loginuid
2016-06-29 15:18:47 -07:00
Richard Guy Briggs 3f5be2da85 audit: move audit_get_tty to reduce scope and kabi changes
The only users of audit_get_tty and audit_put_tty are internal to
audit, so move it out of include/linux/audit.h to kernel.h and create
a proper function rather than inlining it.  This also reduces kABI
changes.

Suggested-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: line wrapped description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-28 15:48:48 -04:00
Richard Guy Briggs 76a658c20e audit: move calcs after alloc and check when logging set loginuid
Move the calculations of values after the allocation in case the
allocation fails.  This avoids wasting effort in the rare case that it
fails, but more importantly saves us extra logic to release the tty
ref.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-28 15:40:17 -04:00
Paul Moore 66b12abc84 audit: fix some horrible switch statement style crimes
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-16 17:08:19 -04:00
Linus Torvalds 03e1aa1cbb Merge branch 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "Four small audit patches for 4.7.

  Two are simple cleanups around the audit thread management code, one
  adds a tty field to AUDIT_LOGIN events, and the final patch makes
  tty_name() usable regardless of CONFIG_TTY.

  Nothing controversial, and it all passes our regression test"

* 'stable-4.7' of git://git.infradead.org/users/pcmoore/audit:
  tty: provide tty_name() even without CONFIG_TTY
  audit: add tty field to LOGIN event
  audit: we don't need to __set_current_state(TASK_RUNNING)
  audit: cleanup prune_tree_thread
2016-05-18 18:46:55 -07:00
Richard Guy Briggs db0a6fb5d9 audit: add tty field to LOGIN event
The tty field was missing from AUDIT_LOGIN events.

Refactor code to create a new function audit_get_tty(), using it to
replace the call in audit_log_task_info() and to add it to
audit_log_set_loginuid().  Lock and bump the kref to protect it, adding
audit_put_tty() alias to decrement it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-04-26 17:19:16 -04:00
Andy Lutomirski efbc0fbf34 auditsc: for seccomp events, log syscall compat state using in_compat_syscall
Except on SPARC, this is what the code always did.  SPARC compat seccomp
was buggy, although the impact of the bug was limited because SPARC
32-bit and 64-bit syscall numbers are the same.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-22 15:36:02 -07:00
Andreas Gruenbacher d6335d77a7 security: Make inode argument of inode_getsecid non-const
Make the inode argument of the inode_getsecid hook non-const so that we
can use it to revalidate invalid security labels.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-12-24 11:09:39 -05:00
Linus Torvalds 425afcff13 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit update from Paul Moore:
 "This is one of the larger audit patchsets in recent history,
  consisting of eight patches and almost 400 lines of changes.

  The bulk of the patchset is the new "audit by executable"
  functionality which allows admins to set an audit watch based on the
  executable on disk.  Prior to this, admins could only track an
  application by PID, which has some obvious limitations.

  Beyond the new functionality we also have some refcnt fixes and a few
  minor cleanups"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  fixup: audit: implement audit by executable
  audit: implement audit by executable
  audit: clean simple fsnotify implementation
  audit: use macros for unset inode and device values
  audit: make audit_del_rule() more robust
  audit: fix uninitialized variable in audit_add_rule()
  audit: eliminate unnecessary extra layer of watch parent references
  audit: eliminate unnecessary extra layer of watch references
2015-09-08 13:34:59 -07:00
Richard Guy Briggs 34d99af52a audit: implement audit by executable
This adds the ability audit the actions of a not-yet-running process.

This patch implements the ability to filter on the executable path.  Instead of
just hard coding the ino and dev of the executable we care about at the moment
the rule is inserted into the kernel, use the new audit_fsnotify
infrastructure to manage this dynamically.  This means that if the filename
does not yet exist but the containing directory does, or if the inode in
question is unlinked and creat'd (aka updated) the rule will just continue to
work.  If the containing directory is moved or deleted or the filesystem is
unmounted, the rule is deleted automatically.  A future enhancement would be to
have the rule survive across directory disruptions.

This is a heavily modified version of a patch originally submitted by Eric
Paris with some ideas from Peter Moody.

Cc: Peter Moody <peter@hda3.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: minor whitespace clean to satisfy ./scripts/checkpatch]
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-08-06 16:17:25 -04:00
Richard Guy Briggs 84cb777e67 audit: use macros for unset inode and device values
Clean up a number of places were casted magic numbers are used to represent
unset inode and device numbers in preparation for the audit by executable path
patch set.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: enclosed the _UNSET macros in parentheses for ./scripts/checkpatch]
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-08-06 14:39:02 -04:00
Linus Torvalds 45820c294f Fix broken audit tests for exec arg len
The "fix" in commit 0b08c5e594 ("audit: Fix check of return value of
strnlen_user()") didn't fix anything, it broke things.  As reported by
Steven Rostedt:

 "Yes, strnlen_user() returns 0 on fault, but if you look at what len is
  set to, than you would notice that on fault len would be -1"

because we just subtracted one from the return value.  So testing
against 0 doesn't test for a fault condition, it tests against a
perfectly valid empty string.

Also fix up the usual braindamage wrt using WARN_ON() inside a
conditional - make it part of the conditional and remove the explicit
unlikely() (which is already part of the WARN_ON*() logic, exactly so
that you don't have to write unreadable code.

Reported-and-tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Paul Moore <pmoore@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-08 09:33:38 -07:00
Linus Torvalds 4a10a91756 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "Four small audit patches for v4.2, all bug fixes.  Only 10 lines of
  change this time so very unremarkable, the patch subject lines pretty
  much tell the whole story"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: Fix check of return value of strnlen_user()
  audit: obsolete audit_context check is removed in audit_filter_rules()
  audit: fix for typo in comment to function audit_log_link_denied()
  lsm: rename duplicate labels in LSM_AUDIT_DATA_TASK audit message type
2015-06-27 13:53:16 -07:00
Jan Kara 0b08c5e594 audit: Fix check of return value of strnlen_user()
strnlen_user() returns 0 when it hits fault, not -1. Fix the test in
audit_log_single_execve_arg(). Luckily this shouldn't ever happen unless
there's a kernel bug so it's mostly a cosmetic fix.

CC: Paul Moore <pmoore@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-06-11 15:49:54 -04:00
Mikhail Klementyev 5c1390c9ff audit: obsolete audit_context check is removed in audit_filter_rules()
Signed-off-by: Mikhail Klementyev <jollheef@riseup.net>
[PM: patch applied by hand due to HTML mangling, rewrote subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-05-29 16:06:47 -04:00
Linus Torvalds 9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Linus Torvalds 27cf3a16b2 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore:
 "Seven audit patches for v4.1, all bug fixes.

  The largest, and perhaps most significant commit helps resolve some
  memory pressure issues related to the inode cache and audit, there are
  also a few small commits which help resolve some timing issues with
  the audit log queue, and the rest fall into the always popular "code
  clean-up" category.

  In general, nothing really substantial, just a nice set of maintenance
  patches"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: Remove condition which always evaluates to false
  audit: reduce mmap_sem hold for mm->exe_file
  audit: consolidate handling of mm->exe_file
  audit: code clean up
  audit: don't reset working wait time accidentally with auditd
  audit: don't lose set wait time on first successful call to audit_log_start()
  audit: move the tree pruning to a dedicated thread
2015-04-22 14:49:23 -07:00
David Howells 3b362157b2 VFS: audit: d_backing_inode() annotations
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:55 -04:00
Davidlohr Bueso 4766b199ef audit: consolidate handling of mm->exe_file
This patch adds a audit_log_d_path_exe() helper function
to share how we handle auditing of the exe_file's path.
Used by both audit and auditsc. No functionality is changed.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-02-23 16:55:47 -05:00
Linus Torvalds 05016b0f0a Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull getname/putname updates from Al Viro:
 "Rework of getname/getname_kernel/etc., mostly from Paul Moore.  Gets
  rid of quite a pile of kludges between namei and audit..."

* 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  audit: replace getname()/putname() hacks with reference counters
  audit: fix filename matching in __audit_inode() and __audit_inode_child()
  audit: enable filename recording via getname_kernel()
  simpler calling conventions for filename_mountpoint()
  fs: create proper filename objects using getname_kernel()
  fs: rework getname_kernel to handle up to PATH_MAX sized filenames
  cut down the number of do_path_lookup() callers
2015-02-17 15:27:47 -08:00
Al Viro f4a4a8b125 file->f_path.dentry is pinned down for as long as the file is open...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:16:27 -05:00
Paul Moore 55422d0bd2 audit: replace getname()/putname() hacks with reference counters
In order to ensure that filenames are not released before the audit
subsystem is done with the strings there are a number of hacks built
into the fs and audit subsystems around getname() and putname().  To
say these hacks are "ugly" would be kind.

This patch removes the filename hackery in favor of a more
conventional reference count based approach.  The diffstat below tells
most of the story; lots of audit/fs specific code is replaced with a
traditional reference count based approach that is easily understood,
even by those not familiar with the audit and/or fs subsystems.

CC: viro@zeniv.linux.org.uk
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-23 00:23:58 -05:00
Paul Moore 57c59f5837 audit: fix filename matching in __audit_inode() and __audit_inode_child()
In all likelihood there were some subtle, and perhaps not so subtle,
bugs with filename matching in audit_inode() and audit_inode_child()
for some time, however, recent changes to the audit filename code have
definitely broken the filename matching code.  The breakage could
result in duplicate filenames in the audit log and other odd audit
record entries.  This patch fixes the filename matching code and
restores some sanity to the filename audit records.

CC: viro@zeniv.linux.org.uk
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-23 00:23:58 -05:00
Paul Moore fd3522fdc8 audit: enable filename recording via getname_kernel()
Enable recording of filenames in getname_kernel() and remove the
kludgy workaround in __audit_inode() now that we have proper filename
logging for kernel users.

CC: viro@zeniv.linux.org.uk
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-23 00:23:52 -05:00
Linus Torvalds 5e0f872c7d Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit fix from Paul Moore:
 "One audit patch to resolve a panic/oops when recording filenames in
  the audit log, see the mail archive link below.

  The fix isn't as nice as I would like, as it involves an allocate/copy
  of the filename, but it solves the problem and the overhead should
  only affect users who have configured audit rules involving file
  names.

  We'll revisit this issue with future kernels in an attempt to make
  this suck less, but in the meantime I think this fix should go into
  the next release of v3.19-rcX.

  [ https://marc.info/?t=141986927600001&r=1&w=2 ]"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: create private file name copies when auditing inodes
2014-12-31 14:52:18 -08:00
Paul Moore fcf22d8267 audit: create private file name copies when auditing inodes
Unfortunately, while commit 4a928436 ("audit: correctly record file
names with different path name types") fixed a problem where we were
not recording filenames, it created a new problem by attempting to use
these file names after they had been freed.  This patch resolves the
issue by creating a copy of the filename which the audit subsystem
frees after it is done with the string.

At some point it would be nice to resolve this issue with refcounts,
or something similar, instead of having to allocate/copy strings, but
that is almost surely beyond the scope of a -rcX patch so we'll defer
that for later.  On the plus side, only audit users should be impacted
by the string copying.

Reported-by: Toralf Foerster <toralf.foerster@gmx.de>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2014-12-30 09:26:21 -05:00
Linus Torvalds 66b3f4f0a0 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore:
 "Four patches to fix various problems with the audit subsystem, all are
  fairly small and straightforward.

  One patch fixes a problem where we weren't using the correct gfp
  allocation flags (GFP_KERNEL regardless of context, oops), one patch
  fixes a problem with old userspace tools (this was broken for a
  while), one patch fixes a problem where we weren't recording pathnames
  correctly, and one fixes a problem with PID based filters.

  In general I don't think there is anything controversial with this
  patchset, and it fixes some rather unfortunate bugs; the allocation
  flag one can be particularly scary looking for users"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: restore AUDIT_LOGINUID unset ABI
  audit: correctly record file names with different path name types
  audit: use supplied gfp_mask from audit_buffer in kauditd_send_multicast_skb
  audit: don't attempt to lookup PIDs when changing PID filtering audit rules
2014-12-23 18:13:16 -08:00