AUDIT: Allow filtering of user messages

Turn the field from a bitmask to an enumeration and add a list to allow 
filtering of messages generated by userspace. We also define a list for 
file system watches in anticipation of that feature.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
AUDIT: Drop user-generated messages immediately while auditing disabled.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Really exempt auditd from having its actions audited.

We were only avoiding it on syscall exit before; now stop _everything_.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Report lookup flags with path/inode records.

When LOOKUP_PARENT is used, the inode which results is not the inode
found at the pathname. Report the flags so that this doesn't generate
misleading audit records.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Spawn kernel thread to list filter rules.

If we have enough rules to fill the netlink buffer space, it'll 
deadlock because auditctl isn't ever actually going to read from the 
socket until we return, and we aren't going to return until it 
reads... so we spawn a kernel thread to spew out the list and then
exit.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Optimise the audit-disabled case for discarding user messages

Also exempt USER_AVC message from being discarded to preserve 
existing behaviour for SE Linux.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Add audit subsystem to MAINTAINERS, for my sins.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Wait for backlog to clear when generating messages.

Add a gfp_mask to audit_log_start() and audit_log(), to reduce the
amount of GFP_ATOMIC allocation -- most of it doesn't need to be 
GFP_ATOMIC. Also if the mask includes __GFP_WAIT, then wait up to
60 seconds for the auditd backlog to clear instead of immediately 
abandoning the message. 

The timeout should probably be made configurable, but for now it'll 
suffice that it only happens if auditd is actually running.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Remove stray declaration of tsk from audit_receive_msg().

It's not used any more.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: No really, we don't want to audit auditd.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Return correct result from audit_filter_rules()

When the task refcounting was added to audit_filter_rules() it became
more of a problem that this function was violating the 'only one 
return from each function' rule. In fixing it to use a variable to store 
'ret' I stupidly neglected to actually change the 'return 1;' at the 
end. This makes it not work very well.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Clean up user message filtering

Don't look up the task by its pid and then use the syscall filtering
helper. Just implement our own filter helper which operates solely on
the information in the netlink_skb_parms. 

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Use KERN_NOTICE for printk of audit records

They aren't errors.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
AUDIT: Fix definition of audit_log_start() if audit not enabled

audit_log_start() seems to take 3 arguments, but its defined to take 
only 2 when AUDIT is turned off.

security/selinux/avc.c:553:75: macro "audit_log_start" passed 3 arguments, but takes just 2

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Fix definition of audit_log() if audit not enabled

audit_log() also takes an extra argument, although it's a vararg 
function so the compiler didn't really notice.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Stop waiting for backlog after audit_panic() happens

We force a rate-limit on auditable events by making them wait for space 
on the backlog queue. However, if auditd really is AWOL then this could 
potentially bring the entire system to a halt, depending on the audit 
rules in effect.

Firstly, make sure the wait time is honoured correctly -- it's the 
maximum time the process should wait, rather than the time to wait 
_each_ time round the loop. We were getting re-woken _each_ time a 
packet was dequeued, and the timeout was being restarted each time.

Secondly, reset the wait time after audit_panic() is called. In general 
this will be reset to zero, to allow progress to be made. If the system
is configured to _actually_ panic on audit_panic() then that will 
already have happened; otherwise we know that audit records are being 
lost anyway. 

These two tunables can't be exposed via AUDIT_GET and AUDIT_SET because 
those aren't particularly well-designed. It probably should have been 
done by sysctls or sysfs anyway -- one for a later patch.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
AUDIT: Really don't audit auditd.

The pid in the audit context isn't always set up. Use tsk->pid when 
checking whether it's auditd in audit_filter_syscall(), instead of 
ctx->pid. Remove a band-aid which did the same elsewhere.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[PATCH] add securityfs for all LSMs to use

Here's a small patch against 2.6.13-rc2 that adds securityfs, a virtual
fs that all LSMs can use instead of creating their own.  The fs should
be mounted at /sys/kernel/security, and the fs creates that mount point.
This will make the LSB people happy that we aren't creating a new
/my_lsm_fs directory in the root for every different LSM.

It has changed a bit since the last version, thanks to comments from
Mike Waychison.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@osdl.org>