From cce64ef01308b677a687d90927fc2b2e0e1cba67 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Wed, 13 Apr 2022 16:10:34 +0100 Subject: [PATCH] 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: 6bf9c47a3989 ("io_uring: defer file assignment") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/2476d4ae46554324b599ee4055447b105f20a75a.1649862516.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 3d6cbf77c89d..d06f1952fdfa 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -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;