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=-7.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 9ED56C433EF for ; Fri, 10 Sep 2021 16:58:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83FDE6108B for ; Fri, 10 Sep 2021 16:58:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230243AbhIJQ7N (ORCPT ); Fri, 10 Sep 2021 12:59:13 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:58643 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230482AbhIJQ7M (ORCPT ); Fri, 10 Sep 2021 12:59:12 -0400 Received: from fsav119.sakura.ne.jp (fsav119.sakura.ne.jp [27.133.134.246]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 18AGvsnc044636; Sat, 11 Sep 2021 01:57:54 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav119.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav119.sakura.ne.jp); Sat, 11 Sep 2021 01:57:54 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav119.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 18AGvsYi044633 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Sat, 11 Sep 2021 01:57:54 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Subject: Re: [syzbot] possible deadlock in bd_register_pending_holders To: syzbot , axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com References: <000000000000e272fb05cba51fe4@google.com> From: Tetsuo Handa Message-ID: Date: Sat, 11 Sep 2021 01:57:53 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <000000000000e272fb05cba51fe4@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Since commit dfbb3409b27fa42b in axboe/linux-block.git#block-5.15 breaks "sb_writers#$N => &p->lock => major_names_lock" dependency chain, I think that this dependency chain should be no longer possible. #syz fix: block: genhd: don't call blkdev_show() with major_names_lock held On 2021/09/10 23:42, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 27151f177827 Merge tag 'perf-tools-for-v5.15-2021-09-04' o.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=104612b3300000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ac2f9cc43f6b17e4 > dashboard link: https://syzkaller.appspot.com/bug?extid=f5608de5d89cc0d998c7 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+f5608de5d89cc0d998c7@syzkaller.appspotmail.com