[PATCH 5.15 22/73] io_uring: fix wrong arm_poll error handling

Greg Kroah-Hartman
2022-09-02T13:00:32Z

From: Pavel Begunkov <asml.silence@gmail.com>

[ upstream commmit 9d2ad2947a53abf5e5e6527a9eeed50a3a4cbc72 ]

Leaving ip.error set when a request was punted to task_work execution is
problematic, don't forget to clear it.

Fixes: aa43477b04025 ("io_uring: poll rework")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a6c84ef4182c6962380aebe11b35bdcb25b0ccfb.1655852245.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[pavel: backport]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/io_uring.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5627,8 +5627,10 @@ static int __io_arm_poll_handler(struct

if (mask) {
/* can't multishot if failed, just queue the event we've got */
- if (unlikely(ipt->error || !ipt->nr_entries))
+ if (unlikely(ipt->error || !ipt->nr_entries)) {
poll->events |= EPOLLONESHOT;
+ ipt->error = 0;
+ }
__io_poll_execute(req, mask);
return 0;
}