diff options
| author | Jan Kara <jack@suse.cz> | 2016-09-19 23:44:30 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-09-20 00:36:17 +0200 |
| commit | 96d41019e3ac55f6f0115b0ce97e4f24a3d636d2 (patch) | |
| tree | 4178f8feee6258da1c08f27de55af8de3f2b5af2 /fs/notify/notification.c | |
| parent | fsnotify: add a way to stop queueing events on group shutdown (diff) | |
| download | linux-96d41019e3ac55f6f0115b0ce97e4f24a3d636d2.tar.xz linux-96d41019e3ac55f6f0115b0ce97e4f24a3d636d2.zip | |
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: 5838d4442bd5 ("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>
Diffstat (limited to 'fs/notify/notification.c')
| -rw-r--r-- | fs/notify/notification.c | 15 |
1 files changed, 0 insertions, 15 deletions
diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 3d76e65ff84f..e455e83ceeeb 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -132,21 +132,6 @@ queue: } /* - * Remove @event from group's notification queue. It is the responsibility of - * the caller to destroy the event. - */ -void fsnotify_remove_event(struct fsnotify_group *group, - struct fsnotify_event *event) -{ - mutex_lock(&group->notification_mutex); - if (!list_empty(&event->list)) { - list_del_init(&event->list); - group->q_len--; - } - mutex_unlock(&group->notification_mutex); -} - -/* * Remove and return the first event from the notification list. It is the * responsibility of the caller to destroy the obtained event */ |