Commit cce64ef0 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: fix poll file assign deadlock 



We pass "unlocked" into io_assign_file() in io_poll_check_events(),
which can lead to double locking.

Fixes: 6bf9c47a ("io_uring: defer file assignment")
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2476d4ae46554324b599ee4055447b105f20a75a.1649862516.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e9419766

fs/io_uring.c

+2 −1
Original line number Diff line number Diff line
@@ -5858,8 +5858,9 @@ static int io_poll_check_events(struct io_kiocb *req, bool locked) 


		if (!req->result) {

			struct poll_table_struct pt = { ._key = req->apoll_events };

			unsigned flags = locked ? 0 : IO_URING_F_UNLOCKED;



			if (unlikely(!io_assign_file(req, IO_URING_F_UNLOCKED)))

			if (unlikely(!io_assign_file(req, flags)))

				req->result = -EBADF;

			else

				req->result = vfs_poll(req->file, &pt) & req->apoll_events;