Commit 21f96522 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: only assign io_uring_enter() SQPOLL error in actual error case 



If an SQPOLL based ring is newly created and an application issues an
io_uring_enter(2) system call on it, then we can return a spurious
-EOWNERDEAD error. This happens because there's nothing to submit, and
if the caller doesn't specify any other action, the initial error
assignment of -EOWNERDEAD never gets overwritten. This causes us to
return it directly, even if it isn't valid.

Move the error assignment into the actual failure case instead.

Cc: stable@vger.kernel.org
Fixes: d9d05217 ("io_uring: stop SQPOLL submit on creator's death")
Reported-by: default avatarSherlock Holo <sherlockya@gmail.com>
Link: https://github.com/axboe/liburing/issues/413


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8f40d037

fs/io_uring.c

+3 −2
Original line number Diff line number Diff line
@@ -9370,9 +9370,10 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, 
	if (ctx->flags & IORING_SETUP_SQPOLL) {

		io_cqring_overflow_flush(ctx, false);



		if (unlikely(ctx->sq_data->thread == NULL)) {

			ret = -EOWNERDEAD;

		if (unlikely(ctx->sq_data->thread == NULL))

			goto out;

		}

		if (flags & IORING_ENTER_SQ_WAKEUP)

			wake_up(&ctx->sq_data->wait);

		if (flags & IORING_ENTER_SQ_WAIT) {