[PATCH 5.15 299/846] io_uring: remove double poll on poll update

From: Greg Kroah-Hartman
Date: Mon Jan 24 2022 - 15:49:11 EST


From: Pavel Begunkov <asml.silence@xxxxxxxxx>

[ Upstream commit e840b4baf3cfb37e2ead4f649a45bb78178677ff ]

Before updating a poll request we should remove it from poll queues,
including the double poll entry.

Fixes: b69de288e913 ("io_uring: allow events and user_data update of running poll requests")
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/ac39e7f80152613603b8a6cc29a2b6063ac2434f.1639605189.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/io_uring.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0006fc7479ca3..ecffeddf90c68 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5925,6 +5925,7 @@ static int io_poll_update(struct io_kiocb *req, unsigned int issue_flags)
* update those. For multishot, if we're racing with completion, just
* let completion re-add it.
*/
+ io_poll_remove_double(preq);
completing = !__io_poll_remove_one(preq, &preq->poll, false);
if (completing && (preq->poll.events & EPOLLONESHOT)) {
ret = -EALREADY;
--
2.34.1