From: Jens Axboe axboe@kernel.dk
commit a36da65c46565d2527eec3efdb546251e38253fd upstream.
Check the ipt.error value, it must have been either cleared to zero or set to another error than the default -EINVAL if we don't go through the waitqueue proc addition. Just give up on poll at that point and return failure, this will fallback to async work.
io_poll_add() doesn't suffer from this failure case, as it returns the error value directly.
Cc: stable@vger.kernel.org # v5.7+ Reported-by: syzbot+a730016dc0bdce4f6ff5@syzkaller.appspotmail.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4483,7 +4483,7 @@ static bool io_arm_poll_handler(struct i
ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, io_async_wake); - if (ret) { + if (ret || ipt.error) { io_poll_remove_double(req, apoll->double_poll); spin_unlock_irq(&ctx->completion_lock); if (req->flags & REQ_F_WORK_INITIALIZED)