[ 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 <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ 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 <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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 <ronny.chevalier@hp.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Check the audit_enabled flag and bail immediately.  This does not change
the functionality, but brings the code format in line with similar
checks in audit_tree_log_remove_rule(), audit_mark_log_rule_change(),
and elsewhere in the audit code.

See: https://github.com/linux-audit/audit-kernel/issues/50

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Pull fsnotify updates from Jan Kara:
 "fsnotify cleanups unifying handling of different watch types.

  This is the shortened fsnotify series from Amir with the last five
  patches pulled out. Amir has modified those patches to not change
  struct inode but obviously it's too late for those to go into this
  merge window"

* tag 'fsnotify_for_v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fsnotify: add fsnotify_add_inode_mark() wrappers
  fanotify: generalize fanotify_should_send_event()
  fsnotify: generalize send_to_group()
  fsnotify: generalize iteration of marks by object type
  fsnotify: introduce marks iteration helpers
  fsnotify: remove redundant arguments to handle_event()
  fsnotify: use type id to identify connector object type

Before changing the arguments of the functions fsnotify_add_mark()
and fsnotify_add_mark_locked(), convert most callers to use a wrapper.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

inode_mark and vfsmount_mark arguments are passed to handle_event()
operation as function arguments as well as on iter_info struct.
The difference is that iter_info struct may contain marks that should
not be handled and are represented as NULL arguments to inode_mark or
vfsmount_mark.

Instead of passing the inode_mark and vfsmount_mark arguments, add
a report_mask member to iter_info struct to indicate which marks should
be handled, versus marks that should only be kept alive during user
wait.

This change is going to be used for passing more mark types
with handle_event() (i.e. super block marks).

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

Recognizing that the audit context is an internal audit value, use an
access function to retrieve the audit context pointer for the task
rather than reaching directly into the task struct to get it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in auditsc.c and selinuxfs.c, checkpatch.pl fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Pull audit fixes from Paul Moore:
 "Two small fixes to the audit code, both explained well in the
  respective patch descriptions, but the quick summary is one
  use-after-free fix, and one silly fanotify notification flag fix"

* tag 'audit-pr-20170816' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: Receive unmount event
  audit: Fix use after free in audit_remove_watch_rule()

Although audit_watch_handle_event() can handle FS_UNMOUNT event, it is
not part of AUDIT_FS_WATCH mask and thus such event never gets to
audit_watch_handle_event(). Thus fsnotify marks are deleted by fsnotify
subsystem on unmount without audit being notified about that which leads
to a strange state of existing audit rules with dead fsnotify marks.

Add FS_UNMOUNT to the mask of events to be received so that audit can
clean up its state accordingly.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <paul@paul-moore.com>