io_uring: only allow submit from owning task
authorJens Axboe <axboe@kernel.dk>
Fri, 17 Jan 2020 02:00:24 +0000 (19:00 -0700)
committerJens Axboe <axboe@kernel.dk>
Fri, 17 Jan 2020 04:43:24 +0000 (21:43 -0700)
commit44d282796f81eb1debc1d7cb53245b4cb3214cb5
treed18a8dca177002a38c5ee979467c3ae2555dc637
parent11ba820bf163e224bf5dd44e545a66a44a5b1d7a
io_uring: only allow submit from owning task

If the credentials or the mm doesn't match, don't allow the task to
submit anything on behalf of this ring. The task that owns the ring can
pass the file descriptor to another task, but we don't want to allow
that task to submit an SQE that then assumes the ring mm and creds if
it needs to go async.

Cc: stable@vger.kernel.org
Suggested-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/io_uring.c