From 76e1b5409e5819eca7b56786e255a2a4758618fb Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 19 Nov 2019 23:32:50 +0300 Subject: [PATCH] io_uring: Fix leaking linked timeouts to #26323578 commit 09fbb0a83ec6ab5a4037766261c031151985fff6 upstream. let have a dependant link: REQ -> LINK_TIMEOUT -> LINK_TIMEOUT 1. submission stage: submission references for REQ and LINK_TIMEOUT are dropped. So, references respectively (1,1,2) 2. io_put(REQ) + FAIL_LINKS stage: calls io_fail_links(), which for all linked timeouts will call cancel_timeout() and drop 1 reference. So, references after: (0,0,1). That's a leak. Make it treat only the first linked timeout as such, and pass others through __io_double_put_req(). Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Joseph Qi Acked-by: Xiaoguang Wang --- fs/io_uring.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index d983cb414ab3..31c4fe426f38 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -947,6 +947,7 @@ static void io_fail_links(struct io_kiocb *req) if ((req->flags & REQ_F_LINK_TIMEOUT) && link->submit.sqe->opcode == IORING_OP_LINK_TIMEOUT) { io_link_cancel_timeout(link); + req->flags &= ~REQ_F_LINK_TIMEOUT; } else { io_cqring_fill_event(link, -ECANCELED); __io_double_put_req(link); -- GitLab