linux/fs/notify/fanotify
Jan Kara 96d41019e3 fanotify: fix list corruption in fanotify_get_response()
fanotify_get_response() calls fsnotify_remove_event() when it finds that
group is being released from fanotify_release() (bypass_perm is set).

However the event it removes need not be only in the group's notification
queue but it can have already moved to access_list (userspace read the
event before closing the fanotify instance fd) which is protected by a
different lock.  Thus when fsnotify_remove_event() races with
fanotify_release() operating on access_list, the list can get corrupted.

Fix the problem by moving all the logic removing permission events from
the lists to one place - fanotify_release().

Fixes: 5838d4442b ("fanotify: fix double free of pending permission events")
Link: http://lkml.kernel.org/r/1473797711-14111-3-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19 15:36:17 -07:00
..
fanotify_user.c fanotify: fix list corruption in fanotify_get_response() 2016-09-19 15:36:17 -07:00
fanotify.c fanotify: fix list corruption in fanotify_get_response() 2016-09-19 15:36:17 -07:00
fanotify.h fanotify: use fanotify event structure for permission response processing 2014-04-03 16:20:51 -07:00
Kconfig treewide: fix typo of "suport" in various comments and Kconfig 2012-11-19 14:16:09 +01:00
Makefile fanotify: fanotify_init syscall declaration 2010-07-28 09:58:55 -04:00