Skip to content
Commit 96d41019 authored by Jan Kara's avatar Jan Kara Committed by Linus Torvalds
Browse files

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: 5838d444 ("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: default avatarJan Kara <jack@suse.cz>
Reported-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Tested-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Reviewed-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 12703dbf
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment