Commit Graph

218 Commits

Author SHA1 Message Date
Dan Duval db89731940 audit: efficiency fix 1: only wake up if queue shorter than backlog limit
These and similar errors were seen on a patched 3.8 kernel when the
audit subsystem was overrun during boot:

  udevd[876]: worker [887] unexpectedly returned with status 0x0100
  udevd[876]: worker [887] failed while handling
'/devices/pci0000:00/0000:00:03.0/0000:40:00.0'
  udevd[876]: worker [880] unexpectedly returned with status 0x0100
  udevd[876]: worker [880] failed while handling
'/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1'

  udevadm settle - timeout of 180 seconds reached, the event queue
contains:
    /sys/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1 (3995)
    /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/INT3F0D:00 (4034)

  audit: audit_backlog=258 > audit_backlog_limit=256
  audit: audit_lost=1 audit_rate_limit=0 audit_backlog_limit=256

The change below increases the efficiency of the audit code and prevents it
from being overrun:

Only issue a wake_up in kauditd if the length of the skb queue is less than the
backlog limit.  Otherwise, threads waiting in wait_for_auditd() will simply
wake up, discover that the queue is still too long for them to proceed, and go
back to sleep.  This results in wasted context switches and machine cycles.
kauditd_thread() is the only function that removes buffers from audit_skb_queue
so we can't race.  If we did, the timeout in wait_for_auditd() would expire and
the waiting thread would continue.

See: https://lkml.org/lkml/2013/9/2/479

Signed-off-by: Dan Duval <dan.duval@oracle.com>
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-13 22:28:08 -05:00
Richard Guy Briggs ae887e0bdc audit: make use of remaining sleep time from wait_for_auditd
If wait_for_auditd() times out, go immediately to the error function rather
than retesting the loop conditions.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-13 22:27:53 -05:00
Richard Guy Briggs e789e561a5 audit: reset audit backlog wait time after error recovery
When the audit queue overflows and times out (audit_backlog_wait_time), the
audit queue overflow timeout is set to zero.  Once the audit queue overflow
timeout condition recovers, the timeout should be reset to the original value.

See also:
	https://lkml.org/lkml/2013/9/2/473

Cc: stable@vger.kernel.org # v3.8-rc4+
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Dan Duval <dan.duval@oracle.com>
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-13 22:27:30 -05:00
Richard Guy Briggs 33faba7fa7 audit: listen in all network namespaces
Convert audit from only listening in init_net to use register_pernet_subsys()
to dynamically manage the netlink socket list.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-13 22:27:24 -05:00
Richard Guy Briggs 2f2ad10133 audit: restore order of tty and ses fields in log output
When being refactored from audit_log_start() to audit_log_task_info(), in
commit e23eb920 the tty and ses fields in the log output got transposed.
Restore to original order to avoid breaking search tools.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-13 22:27:16 -05:00
Richard Guy Briggs f9441639e6 audit: fix netlink portid naming and types
Normally, netlink ports use the PID of the userspace process as the port ID.
If the PID is already in use by a port, the kernel will allocate another port
ID to avoid conflict.  Re-name all references to netlink ports from pid to
portid to reflect this reality and avoid confusion with actual PIDs.  Ports
use the __u32 type, so re-type all portids accordingly.

(This patch is very similar to ebiederman's 5deadd69)

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-13 22:26:52 -05:00
Eric Paris fc582aef7d Merge tag 'v3.12'
Linux 3.12

Conflicts:
	fs/exec.c
2013-11-22 18:57:54 -05:00
Jeff Layton d3aea84a4a audit: log the audit_names record type
...to make it clear what the intent behind each record's operation was.

In many cases you can infer this, based on the context of the syscall
and the result. In other cases it's not so obvious. For instance, in
the case where you have a file being renamed over another, you'll have
two different records with the same filename but different inode info.
By logging this information we can clearly tell which one was created
and which was deleted.

This fixes what was broken in commit bfcec708.
Commit 79f6530c should also be backported to stable v3.7+.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:09:04 -05:00
Richard Guy Briggs b95d77fe34 audit: use given values in tty_audit enable api
In send/GET, we don't want the kernel to lie about what value is set.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:42 -05:00
Mathias Krause 4d8fe7376a audit: use nlmsg_len() to get message payload length
Using the nlmsg_len member of the netlink header to test if the message
is valid is wrong as it includes the size of the netlink header itself.
Thereby allowing to send short netlink messages that pass those checks.

Use nlmsg_len() instead to test for the right message length. The result
of nlmsg_len() is guaranteed to be non-negative as the netlink message
already passed the checks of nlmsg_ok().

Also switch to min_t() to please checkpatch.pl.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org  # v2.6.6+ for the 1st hunk, v2.6.23+ for the 2nd
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:37 -05:00
Eric Paris e13f91e3c5 audit: use memset instead of trying to initialize field by field
We currently are setting fields to 0 to initialize the structure
declared on the stack.  This is a bad idea as if the structure has holes
or unpacked space these will not be initialized.  Just use memset.  This
is not a performance critical section of code.

Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:35 -05:00
Mathias Krause 64fbff9ae0 audit: fix info leak in AUDIT_GET requests
We leak 4 bytes of kernel stack in response to an AUDIT_GET request as
we miss to initialize the mask member of status_set. Fix that.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org  # v2.6.6+
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:30 -05:00
Eric Paris 21b85c31d2 audit: audit feature to set loginuid immutable
This adds a new 'audit_feature' bit which allows userspace to set it
such that the loginuid is absolutely immutable, even if you have
CAP_AUDIT_CONTROL.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:17 -05:00
Eric Paris d040e5af38 audit: audit feature to only allow unsetting the loginuid
This is a new audit feature which only grants processes with
CAP_AUDIT_CONTROL the ability to unset their loginuid.  They cannot
directly set it from a valid uid to another valid uid.  The ability to
unset the loginuid is nice because a priviledged task, like that of
container creation, can unset the loginuid and then priv is not needed
inside the container when a login daemon needs to set the loginuid.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:13 -05:00
Eric Paris b0fed40214 audit: implement generic feature setting and retrieving
The audit_status structure was not designed with extensibility in mind.
Define a new AUDIT_SET_FEATURE message type which takes a new structure
of bits where things can be enabled/disabled/locked one at a time.  This
structure should be able to grow in the future while maintaining forward
and backward compatibility (based loosly on the ideas from capabilities
and prctl)

This does not actually add any features, but is just infrastructure to
allow new on/off types of audit system features.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:30 -05:00
Tyler Hicks 0868a5e150 audit: printk USER_AVC messages when audit isn't enabled
When the audit=1 kernel parameter is absent and auditd is not running,
AUDIT_USER_AVC messages are being silently discarded.

AUDIT_USER_AVC messages should be sent to userspace using printk(), as
mentioned in the commit message of 4a4cd633 ("AUDIT: Optimise the
audit-disabled case for discarding user messages").

When audit_enabled is 0, audit_receive_msg() discards all user messages
except for AUDIT_USER_AVC messages. However, audit_log_common_recv_msg()
refuses to allocate an audit_buffer if audit_enabled is 0. The fix is to
special case AUDIT_USER_AVC messages in both functions.

It looks like commit 50397bd1 ("[AUDIT] clean up audit_receive_msg()")
introduced this bug.

Cc: <stable@kernel.org> # v2.6.25+
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-audit@redhat.com
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:23 -05:00
Gao feng af0e493d30 Audit: remove duplicate comments
Remove it.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:14 -05:00
Richard Guy Briggs b8f89caafe audit: remove newline accidentally added during session id helper refactor
A newline was accidentally added during session ID helper refactorization in
commit 4d3fb709.  This needlessly uses up buffer space, messes up syslog
formatting and makes userspace processing less efficient.  Remove it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:09 -05:00
Ilya V. Matveychikov 47145705e3 audit: remove duplicate inclusion of the netlink header
Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:06:53 -05:00
Richard Guy Briggs b50eba7e2d audit: format user messages to size of MAX_AUDIT_MESSAGE_LENGTH
Messages of type AUDIT_USER_TTY were being formatted to 1024 octets,
truncating messages approaching MAX_AUDIT_MESSAGE_LENGTH (8970 octets).

Set the formatting to 8560 characters, given maximum estimates for prefix and
suffix budgets.

See the problem discussion:
https://www.redhat.com/archives/linux-audit/2009-January/msg00030.html

And the new size rationale:
https://www.redhat.com/archives/linux-audit/2013-September/msg00016.html

Test ~8k messages with:
auditctl -m "$(for i in $(seq -w 001 820);do echo -n "${i}0______";done)"

Reported-by: LC Bruzenak <lenny@magitekltd.com>
Reported-by: Justin Stephenson <jstephen@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:06:49 -05:00
Konstantin Khlebnikov 8ac1c8d5de audit: fix endless wait in audit_log_start()
After commit 829199197a ("kernel/audit.c: avoid negative sleep
durations") audit emitters will block forever if userspace daemon cannot
handle backlog.

After the timeout the waiting loop turns into busy loop and runs until
daemon dies or returns back to work.  This is a minimal patch for that
bug.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Chuck Anderson <chuck.anderson@oracle.com>
Cc: Dan Duval <dan.duval@oracle.com>
Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 17:00:26 -07:00
Oleg Nesterov f000cfdde5 audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE
audit_log_start() does wait_for_auditd() in a loop until
audit_backlog_wait_time passes or audit_skb_queue has a room.

If signal_pending() is true this becomes a busy-wait loop, schedule() in
TASK_INTERRUPTIBLE won't block.

Thanks to Guy for fully investigating and explaining the problem.

(akpm: that'll cause the system to lock up on a non-preemptible
uniprocessor kernel)

(Guy: "Our customer was in fact running a uniprocessor machine, and they
reported a system hang.")

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Guy Streeter <streeter@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-12 16:29:45 -07:00
Linus Torvalds c4cc75c332 Merge git://git.infradead.org/users/eparis/audit
Pull audit changes from Eric Paris:
 "Al used to send pull requests every couple of years but he told me to
  just start pushing them to you directly.

  Our touching outside of core audit code is pretty straight forward.  A
  couple of interface changes which hit net/.  A simple argument bug
  calling audit functions in namei.c and the removal of some assembly
  branch prediction code on ppc"

* git://git.infradead.org/users/eparis/audit: (31 commits)
  audit: fix message spacing printing auid
  Revert "audit: move kaudit thread start from auditd registration to kaudit init"
  audit: vfs: fix audit_inode call in O_CREAT case of do_last
  audit: Make testing for a valid loginuid explicit.
  audit: fix event coverage of AUDIT_ANOM_LINK
  audit: use spin_lock in audit_receive_msg to process tty logging
  audit: do not needlessly take a lock in tty_audit_exit
  audit: do not needlessly take a spinlock in copy_signal
  audit: add an option to control logging of passwords with pam_tty_audit
  audit: use spin_lock_irqsave/restore in audit tty code
  helper for some session id stuff
  audit: use a consistent audit helper to log lsm information
  audit: push loginuid and sessionid processing down
  audit: stop pushing loginid, uid, sessionid as arguments
  audit: remove the old depricated kernel interface
  audit: make validity checking generic
  audit: allow checking the type of audit message in the user filter
  audit: fix build break when AUDIT_DEBUG == 2
  audit: remove duplicate export of audit_enabled
  Audit: do not print error when LSMs disabled
  ...
2013-05-11 14:29:11 -07:00
Eric Paris 2a0b4be6dd audit: fix message spacing printing auid
The helper function didn't include a leading space, so it was jammed
against the previous text in the audit record.

Signed-off-by: Eric Paris <eparis@redhat.com>
2013-05-08 00:02:19 -04:00
Eric Paris 82d8da0d46 Revert "audit: move kaudit thread start from auditd registration to kaudit init"
This reverts commit 6ff5e45985.

Conflicts:
	kernel/audit.c

This patch was starting a kthread for all the time.  Since the follow on
patches that required it didn't get finished in 3.10 time, we shouldn't
ship this change in 3.10.

Signed-off-by: Eric Paris <eparis@redhat.com>
2013-05-07 22:27:21 -04:00