In this implementation, audit registers inotify watches on the parent
directories of paths specified in audit rules. When audit's inotify
event handler is called, it updates any affected rules based on the
filesystem event. If the parent directory is renamed, removed, or its
filesystem is unmounted, audit removes all rules referencing that
inotify watch.
To keep things simple, this implementation limits location-based
auditing to the directory entries in an existing directory. Given
a path-based rule for /foo/bar/passwd, the following table applies:
passwd modified -- audit event logged
passwd replaced -- audit event logged, rules list updated
bar renamed -- rule removed
foo renamed -- untracked, meaning that the rule now applies to
the new location
Audit users typically want to have many rules referencing filesystem
objects, which can significantly impact filtering performance. This
patch also adds an inode-number-based rule hash to mitigate this
situation.
The patch is relative to the audit git tree:
http://kernel.org/git/?p=linux/kernel/git/viro/audit-current.git;a=summary
and uses the inotify kernel API:
http://lkml.org/lkml/2006/6/1/145
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Don't return -ENOMEM when callers of these functions are checking for
a NULL return. Bug noticed by Serge Hallyn.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We should not send a pile of replies while holding audit_netlink_mutex
since we hold the same mutex when we receive commands. As the result,
we can get blocked while sending and sit there holding the mutex while
auditctl is unable to send the next command and get around to receiving
what we'd sent.
Solution: create skb and put them into a queue instead of sending;
once we are done, send what we've got on the list. The former can
be done synchronously while we are handling AUDIT_LIST or AUDIT_LIST_RULES;
we are holding audit_netlink_mutex at that point. The latter is done
asynchronously and without messing with audit_netlink_mutex.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hi,
The patch below builds upon the patch sent earlier and adds subject label to
all audit events generated via the netlink interface. It also cleans up a few
other minor things.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch provides the ability to filter audit messages based on the
elements of the process' SELinux context (user, role, type, mls sensitivity,
and mls clearance). It uses the new interfaces from selinux to opaquely
store information related to the selinux context and to filter based on that
information. It also uses the callback mechanism provided by selinux to
refresh the information when a new policy is loaded.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Darrel Goeddel initiated a discussion on IRC regarding the possibility
of audit_comparator() returning -EINVAL signaling an invalid operator.
It is possible when creating the rule to assure that the operator is one
of the 6 sane values. Here's a snip from include/linux/audit.h Note
that 0 (nonsense) and 7 (all operators) are not valid values for an
operator.
...
/* These are the supported operators.
* 4 2 1
* = > <
* -------
* 0 0 0 0 nonsense
* 0 0 1 1 <
* 0 1 0 2 >
* 0 1 1 3 !=
* 1 0 0 4 =
* 1 0 1 5 <=
* 1 1 0 6 >=
* 1 1 1 7 all operators
*/
...
Furthermore, prior to adding these extended operators, flagging the
AUDIT_NEGATE bit implied !=, and otherwise == was assumed.
The following code forces the operator to be != if the AUDIT_NEGATE bit
was flipped on. And if no operator was specified, == is assumed. The
only invalid condition is if the AUDIT_NEGATE bit is off and all of the
AUDIT_EQUAL, AUDIT_LESS_THAN, and AUDIT_GREATER_THAN bits are
on--clearly a nonsensical operator.
Now that this is handled at rule insertion time, the default -EINVAL
return of audit_comparator() is eliminated such that the function can
only return 1 or 0.
If this is acceptable, let's get this applied to the current tree.
:-Dustin
--
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
(cherry picked from 9bf0a8e137040f87d1b563336d4194e38fb2ba1a commit)
Hi,
The following patch adds a little more information to the add/remove rule message emitted
by the kernel.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This fixes the per-user and per-message-type filtering when syscall
auditing isn't enabled.
[AV: folded followup fix from the same author]
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
