linux-stable.git/kernel/audit_watch.c, branch v4.9.321

audit: CONFIG_CHANGE don't log internal bookkeeping as an event

2020-10-01T18:40:07+00:00

[ Upstream commit 70b3eeed49e8190d97139806f6fbaf8964306cdb ]

Common Criteria calls out for any action that modifies the audit trail to
be recorded. That usually is interpreted to mean insertion or removal of
rules. It is not required to log modification of the inode information
since the watch is still in effect. Additionally, if the rule is a never
rule and the underlying file is one they do not want events for, they
get an event for this bookkeeping update against their wishes.

Since no device/inode info is logged at insertion and no device/inode
information is logged on update, there is nothing meaningful being
communicated to the admin by the CONFIG_CHANGE updated_rules event. One
can assume that the rule was not "modified" because it is still watching
the intended target. If the device or inode cannot be resolved, then
audit_panic is called which is sufficient.

The correct resolution is to drop logging config_update events since
the watch is still in effect but just on another unknown inode.

Signed-off-by: Steve Grubb 
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin

audit_get_nd(): don't unlock parent too early

2019-12-21T09:40:48+00:00

[ Upstream commit 69924b89687a2923e88cc42144aea27868913d0e ]

if the child has been negative and just went positive
under us, we want coherent d_is_positive() and ->d_inode.
Don't unlock the parent until we'd done that work...

Signed-off-by: Al Viro 
Signed-off-by: Sasha Levin

audit: fix use-after-free in audit_add_watch

2018-09-26T06:36:37+00:00

[ Upstream commit baa2a4fdd525c8c4b0f704d20457195b29437839 ]

audit_add_watch stores locally krule->watch without taking a reference
on watch. Then, it calls audit_add_to_parent, and uses the watch stored
locally.

Unfortunately, it is possible that audit_add_to_parent updates
krule->watch.
When it happens, it also drops a reference of watch which
could free the watch.

How to reproduce (with KASAN enabled):

    auditctl -w /etc/passwd -F success=0 -k test_passwd
    auditctl -w /etc/passwd -F success=1 -k test_passwd2

The second call to auditctl triggers the use-after-free, because
audit_to_parent updates krule->watch to use a previous existing watch
and drops the reference to the newly created watch.

To fix the issue, we grab a reference of watch and we release it at the
end of the function.

Signed-off-by: Ronny Chevalier 
Reviewed-by: Richard Guy Briggs 
Signed-off-by: Paul Moore 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

audit: Fix use after free in audit_remove_watch_rule()

2017-08-25T00:12:18+00:00

commit d76036ab47eafa6ce52b69482e91ca3ba337d6d6 upstream.

audit_remove_watch_rule() drops watch's reference to parent but then
continues to work with it. That is not safe as parent can get freed once
we drop our reference. The following is a trivial reproducer:

mount -o loop image /mnt
touch /mnt/file
auditctl -w /mnt/file -p wax
umount /mnt
auditctl -D


Grab our own reference in audit_remove_watch_rule() earlier to make sure
mark does not get freed under us.

Reported-by: Tony Jones 
Signed-off-by: Jan Kara 
Tested-by: Tony Jones 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit

2016-09-01T22:55:56+00:00

Pull audit fixes from Paul Moore:
 "Two small patches to fix some bugs with the audit-by-executable
  functionality we introduced back in v4.3 (both patches are marked
  for the stable folks)"

* 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit:
  audit: fix exe_file access in audit_exe_compare
  mm: introduce get_task_exe_file

audit: fix exe_file access in audit_exe_compare

2016-08-31T20:16:35+00:00

Prior to the change the function would blindly deference mm, exe_file
and exe_file->f_inode, each of which could have been NULL or freed.

Use get_task_exe_file to safely obtain stable exe_file.

Signed-off-by: Mateusz Guzik 
Acked-by: Konstantin Khlebnikov 
Acked-by: Richard Guy Briggs 
Cc:  # 4.3.x
Signed-off-by: Paul Moore

don't bother with ->d_inode->i_sb - it's always equal to ->d_sb

2016-04-10T21:11:51+00:00

... and neither can ever be NULL

Signed-off-by: Al Viro

Merge branch 'stable-4.6' of git://git.infradead.org/users/pcmoore/audit

2016-03-20T00:52:49+00:00

Pull audit updates from Paul Moore:
 "A small set of patches for audit this time; just three in total and
  one is a spelling fix.

  The two patches with actual content are designed to help prevent new
  instances of auditd from displacing an existing, functioning auditd
  and to generate a log of the attempt.  Not to worry, dead/stuck auditd
  instances can still be replaced by a new instance without problem.

  Nothing controversial, and everything passes our regression suite"

* 'stable-4.6' of git://git.infradead.org/users/pcmoore/audit:
  audit: Fix typo in comment
  audit: log failed attempts to change audit_pid configuration
  audit: stop an old auditd being starved out by a new auditd

audit: Fix typo in comment

2016-02-08T16:25:39+00:00

Signed-off-by: Weiyuan 
Signed-off-by: Paul Moore

wrappers for ->i_mutex access

2016-01-22T23:04:28+00:00

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro