diff options
| author | Jens Axboe <axboe@kernel.dk> | 2020-01-16 19:00:24 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-01-16 21:43:24 -0700 |
| commit | 44d282796f81eb1debc1d7cb53245b4cb3214cb5 (patch) | |
| tree | d18a8dca177002a38c5ee979467c3ae2555dc637 | |
| parent | 11ba820bf163e224bf5dd44e545a66a44a5b1d7a (diff) | |
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>
| -rw-r--r-- | fs/io_uring.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 52e5764540e4..187dd94fd6b1 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5159,6 +5159,12 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } else if (to_submit) { struct mm_struct *cur_mm; + if (current->mm != ctx->sqo_mm || + current_cred() != ctx->creds) { + ret = -EPERM; + goto out; + } + to_submit = min(to_submit, ctx->sq_entries); mutex_lock(&ctx->uring_lock); /* already have mm, so io_submit_sqes() won't try to grab it */ |