Using the generic kernel function causes the
object size to increase with gcc 4.8.1.

$ size kernel/audit.o*
   text	   data	    bss	    dec	    hex	filename
  18577	   6079	   8436	  33092	   8144	kernel/audit.o.new
  18579	   6015	   8420	  33014	   80f6	kernel/audit.o.old

Unsigned...

An admin is likely to want to see old and new values next to each other.
Putting all of the old values followed by all of the new values is just
hard to read as a human.
Signed-off-by: NEric Paris <eparis@redhat.com>

We can simplify the AUDIT_TTY_SET code to only grab the spin_lock one
time.  We need to determine if the new values are valid and if so, set
the new values at the same time we grab the old onces.  While we are
here get rid of 'res' and just use err.
Signed-off-by: NEric Paris <eparis@redhat.com>

If userspace specified that it was setting values via the mask we do not
need a second check to see if they also set the version field high
enough to understand those values.  (clearly if they set the mask they
knew those values).
Signed-off-by: NEric Paris <eparis@redhat.com>

Give names to the audit versions.  Just something for a userspace
programmer to know what the version provides.
Signed-off-by: NEric Paris <eparis@redhat.com>

We had some craziness with signed to unsigned long casting which appears
wholely unnecessary.  Just use signed long.  Even though 2 values of the
math equation are unsigned longs the result is expected to be a signed
long.  So why keep casting the result to signed long?  Just make it
signed long and use it.

We also remove the needless "timeout" variable.  We already have the
stack "sleep_time" variable.  Just use that...
Signed-off-by: NEric Paris <eparis@redhat.com>

Add task information to the log when changing a feature state.
Signed-off-by: NEric Paris <eparis@redhat.com>

NETLINK_CB(skb).sk is the socket of user space process,
netlink_unicast in kauditd_send_skb wants the kernel
side socket. Since the sk_state of audit netlink socket
is not NETLINK_CONNECTED, so the netlink_getsockbyportid
doesn't return -ECONNREFUSED.

And the socket of userspace process can be released anytime,
so the audit_sock may point to invalid socket.

this patch sets the audit_sock to the kernel side audit
netlink socket.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

print the error message and then return -ENOMEM.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

An error on an AUDIT_NEVER rule disabled logging on that rule.
On error on AUDIT_NEVER rules, log.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

The backlog cannot be consumed when audit_log_start is running on auditd
even if audit_log_start calls wait_for_auditd to consume it.
The situation is the deadlock because only auditd can consume the backlog.
If the other process needs to send the backlog, it can be also stopped
by the deadlock.

So, audit_log_start running on auditd should not stop.

You can see the deadlock with the following reproducer:
 # auditctl -a exit,always -S all
 # reboot
Signed-off-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Reviewed-by: gaofeng@cn.fujitsu.com
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

We do not need to hold the audit_cmd_mutex for this family of cases.  The
possible exception to this is the call to audit_filter_user(), so drop the lock
immediately after.  To help in fixing the race we are trying to avoid, make
sure that nothing called by audit_filter_user() calls audit_log_start().  In
particular, watch out for *_audit_rule_match().

This fix will take care of systemd and anything USING audit.  It still means
that we could race with something configuring audit and auditd shutting down.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Reported-by: toshi.okajima@jp.fujitsu.com
Tested-by: toshi.okajima@jp.fujitsu.com
Signed-off-by: NEric Paris <eparis@redhat.com>

Right now the sessionid value in the kernel is a combination of u32,
int, and unsigned int.  Just use unsigned int throughout.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

Currently when the coredump signals are logged by the audit system, the
actual path to the executable is not logged. Without details of exe, the
system admin may not have an exact idea on what program failed.

This patch changes the audit_log_task() so that the path to the exe is also
logged.

This was copied from audit_log_task_info() and the latter enhanced to avoid
disappearing text fields.
Signed-off-by: NPaul Davies C <pauldaviesc@gmail.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

There have been reports of auditd restarts resulting in kaudit not being able
to find a newly registered auditd.  It results in reports such as:
	kernel: [ 2077.233573] audit: *NO* daemon at audit_pid=1614
	kernel: [ 2077.234712] audit: audit_lost=97 audit_rate_limit=0 audit_backlog_limit=320
	kernel: [ 2077.234718] audit: auditd disappeared
		(previously mis-spelled "dissapeared")

One possible cause is a race between the shutdown of an older auditd and a
newer one.  If the newer one sets the daemon pid to itself in kauditd before
the older one has cleared the daemon pid, the newer daemon pid will be erased.
This could be caused by an automated system, or by manual intervention, but in
either case, there is no use in having the older daemon clear the daemon pid
reference since its old pid is no longer being referenced.  This patch will
prevent that specific case, returning an error of EACCES.

The case for preventing a newer auditd from registering itself if there is an
existing auditd is a more difficult case that is beyond the scope of this
patch.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

audit_receive_msg() needlessly contained a fallthrough case that called
audit_receive_filter(), containing no common code between the cases.  Separate
them to make the logic clearer.  Refactor AUDIT_LIST_RULES, AUDIT_ADD_RULE,
AUDIT_DEL_RULE cases to create audit_rule_change(), audit_list_rules_send()
functions.  This should not functionally change the logic.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

Log transition of config changes when AUDIT_TTY_SET is called, including both
enabled and log_passwd values now in the struct.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

kauditd_send_skb is called after audit_pid was checked to be non-zero.

However, it can be set to 0 due to auditd exiting while kauditd_send_skb
is still executed and this can result in a spurious warning about missing
auditd.

Re-check audit_pid before printing the message.
Signed-off-by: NMateusz Guzik <mguzik@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

Since audit can already be disabled by "audit=0" on the kernel boot line, or by
the command "auditctl -e 0", it would be more useful to have the
audit_backlog_limit set to zero mean effectively unlimited (limited only by
system RAM).
Acked-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

we already have old_lock, no need to calculate it again.
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

If audit is disabled,we shouldn't generate the audit log.
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

The order of new feature and old feature is incorrect,
this patch fix it.
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

Since kernel parameter is operated before
initcall, so the audit_initialized must be
AUDIT_UNINITIALIZED or DISABLED in audit_enable.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

reaahead-collector abuses the audit logging facility to discover which files
are accessed at boot time to make a pre-load list

Add a tuning option to audit_backlog_wait_time so that if auditd can't keep up,
or gets blocked, the callers won't be blocked.

Bump audit_status API version to "2".
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

Re-named confusing local variable names (status_set and status_get didn't agree
with their command type name) and reduced their scope.

Future-proof API changes by not depending on the exact size of the audit_status
struct and by adding an API version field.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

The default audit_backlog_limit is 64.  This was a reasonable limit at one time.

systemd causes so much audit queue activity on startup that auditd doesn't
start before the backlog queue has already overflowed by more than a factor of
2.  On a system with audit= not set on the kernel command line, this isn't an
issue since that history isn't kept for auditd when it is available.  On a
system with audit=1 set on the kernel command line, kaudit tries to keep that
history until auditd is able to drain the queue.

This default can be changed by the "-b" option in audit.rules once the system
has booted, but won't help with lost messages on boot.

One way to solve this would be to increase the default backlog queue size to
avoid losing any messages before auditd is able to consume them.  This would
be overkill to the embedded community and insufficient for some servers.

Another way to solve it might be to add a kconfig option to set the default
based on the system type.  An embedded system would get the current (or
smaller) default, while Workstations might get more than now and servers might
get more.

None of these solutions helps if a system's compiled default is too small to
see the lost messages without compiling a new kernel.

This patch adds a kernel set-up parameter (audit already has one to
enable/disable it) "audit_backlog_limit=<n>" that overrides the default to
allow the system administrator to set the backlog limit.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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:

Use add_wait_queue_exclusive() in wait_for_auditd() to put the
thread on the wait queue.  When kauditd dequeues an skb, all
of the waiting threads are waiting for the same resource, but
only one is going to get it, so there's no need to wake up
more than one waiter.

See: https://lkml.org/lkml/2013/9/2/479Signed-off-by: NDan Duval <dan.duval@oracle.com>
Signed-off-by: NChuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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/2013/9/2/479Signed-off-by: NDan Duval <dan.duval@oracle.com>
Signed-off-by: NChuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

If wait_for_auditd() times out, go immediately to the error function rather
than retesting the loop conditions.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NDan Duval <dan.duval@oracle.com>
Signed-off-by: NChuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

Convert audit from only listening in init_net to use register_pernet_subsys()
to dynamically manage the netlink socket list.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

...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: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

In send/GET, we don't want the kernel to lie about what value is set.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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: NEric Paris <eparis@redhat.com>

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: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>