linux/fs/notify
Jan Kara a2673b6e04 fsnotify: fix oops in fsnotify_clear_marks_by_group_flags()
fsnotify_clear_marks_by_group_flags() can race with
fsnotify_destroy_marks() so when fsnotify_destroy_mark_locked() drops
mark_mutex, a mark from the list iterated by
fsnotify_clear_marks_by_group_flags() can be freed and we dereference free
memory in the loop there.

Fix the problem by keeping mark_mutex held in
fsnotify_destroy_mark_locked().  The reason why we drop that mutex is that
we need to call a ->freeing_mark() callback which may acquire mark_mutex
again.  To avoid this and similar lock inversion issues, we move the call
to ->freeing_mark() callback to the kthread destroying the mark.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Ashish Sangwan <a.sangwan@samsung.com>
Suggested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-17 16:39:54 -07:00
..
dnotify fsnotify: unify inode and mount marks handling 2014-12-13 12:42:53 -08:00
fanotify fanotify: fix event filtering with FAN_ONDIR set 2015-03-12 18:46:08 -07:00
inotify fs/notify: don't use module_init for non-modular inotify_user code 2015-06-16 14:12:34 -04:00
Kconfig rcu: Make SRCU optional by using CONFIG_SRCU 2015-01-06 11:04:29 -08:00
Makefile fs, notify: add procfs fdinfo helper 2012-12-17 17:15:28 -08:00
fdinfo.c fsnotify: unify inode and mount marks handling 2014-12-13 12:42:53 -08:00
fdinfo.h fs: Convert show_fdinfo functions to void 2014-11-05 14:13:23 -05:00
fsnotify.c fsnotify: unify inode and mount marks handling 2014-12-13 12:42:53 -08:00
fsnotify.h fsnotify: unify inode and mount marks handling 2014-12-13 12:42:53 -08:00
group.c fs/notify/group.c: make fsnotify_final_destroy_group() static 2014-10-09 22:25:45 -04:00
inode_mark.c fsnotify: unify inode and mount marks handling 2014-12-13 12:42:53 -08:00
mark.c fsnotify: fix oops in fsnotify_clear_marks_by_group_flags() 2015-07-17 16:39:54 -07:00
notification.c fanotify: fix double free of pending permission events 2014-08-06 18:01:12 -07:00
vfsmount_mark.c fsnotify: unify inode and mount marks handling 2014-12-13 12:42:53 -08:00