From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 314D8C47082 for ; Tue, 8 Jun 2021 19:24:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1ABFC61185 for ; Tue, 8 Jun 2021 19:24:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236363AbhFHT0r (ORCPT ); Tue, 8 Jun 2021 15:26:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:58764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236304AbhFHTNz (ORCPT ); Tue, 8 Jun 2021 15:13:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BB27461959; Tue, 8 Jun 2021 18:49:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623178195; bh=weSRea2QOkWVWpA1lEqEn9Cg7/2yqFa+Gce8M538pxQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U17GE7+YecRSk9hOILi1CbuUZEGLnsIzZLk9p2KSzVtTNxbr025x5G2zyrGsexHt3 eM7La5NoruRYDxO27IpRmXOZCkcngsk/T9/gheYEUh3EagnPlASJ49k/fUyqlmgrT6 6oNxMBvkNr+Mi1ZFV2GHmHFd0f4LBDxG9hgnG4hM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+a2910119328ce8e7996f@syzkaller.appspotmail.com, Pavel Begunkov , Jens Axboe , Sasha Levin Subject: [PATCH 5.12 085/161] io_uring: fix link timeout refs Date: Tue, 8 Jun 2021 20:26:55 +0200 Message-Id: <20210608175948.308619441@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210608175945.476074951@linuxfoundation.org> References: <20210608175945.476074951@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Begunkov [ Upstream commit a298232ee6b9a1d5d732aa497ff8be0d45b5bd82 ] WARNING: CPU: 0 PID: 10242 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] io_put_req fs/io_uring.c:2140 [inline] io_queue_linked_timeout fs/io_uring.c:6300 [inline] __io_queue_sqe+0xbef/0xec0 fs/io_uring.c:6354 io_submit_sqe fs/io_uring.c:6534 [inline] io_submit_sqes+0x2bbd/0x7c50 fs/io_uring.c:6660 __do_sys_io_uring_enter fs/io_uring.c:9240 [inline] __se_sys_io_uring_enter+0x256/0x1d60 fs/io_uring.c:9182 io_link_timeout_fn() should put only one reference of the linked timeout request, however in case of racing with the master request's completion first io_req_complete() puts one and then io_put_req_deferred() is called. Cc: stable@vger.kernel.org # 5.12+ Fixes: 9ae1f8dd372e0 ("io_uring: fix inconsistent lock state") Reported-by: syzbot+a2910119328ce8e7996f@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/ff51018ff29de5ffa76f09273ef48cb24c720368.1620417627.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/io_uring.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 144056b0cac9..89f4e5e80b9e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6272,6 +6272,7 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) if (prev) { io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME); io_put_req_deferred(prev, 1); + io_put_req_deferred(req, 1); } else { io_req_complete_post(req, -ETIME, 0); io_put_req_deferred(req, 1); -- 2.30.2