commit 3587b1b097d70c2eb9fee95ea7995d13c05f66e5
author Al Viro <viro@ZenIV.linux.org.uk> Sun Nov 18 19:19:00 2012 +0000
committer Linus Torvalds <torvalds@linux-foundation.org> Sun Nov 18 09:30:00 2012 -1000
tree 71f29d988cb6a1ac7f1c258dc003a9d252ea72f6
parent 8d938105e432fe0e9f5163147e9c113190bd9d32

fanotify: fix FAN_Q_OVERFLOW case of fanotify_read()

If the FAN_Q_OVERFLOW bit set in event->mask, the fanotify event
metadata will not contain a valid file descriptor, but
copy_event_to_user() didn't check for that, and unconditionally does a
fd_install() on the file descriptor.

Which in turn will cause a BUG_ON() in __fd_install().

Introduced by commit 352e3b249284 ("fanotify: sanitize failure exits in
copy_event_to_user()")

Mea culpa - missed that path ;-/

Reported-by: Alex Shi <lkml.alex@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>