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=-10.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 19582C433DB for ; Wed, 10 Feb 2021 03:03:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E060664E4E for ; Wed, 10 Feb 2021 03:03:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233162AbhBJDDC (ORCPT ); Tue, 9 Feb 2021 22:03:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232557AbhBJDC7 (ORCPT ); Tue, 9 Feb 2021 22:02:59 -0500 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D3E8C061574 for ; Tue, 9 Feb 2021 19:02:13 -0800 (PST) Received: by mail-pl1-x636.google.com with SMTP id s15so407963plr.9 for ; Tue, 09 Feb 2021 19:02:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=V10BJdzxHAV0h7gQUJltJC4aCoH9Xjs54AoTSTl4hSI=; b=B3QvcCQEy6cR9gkJxqSGDQpsdvdK0oByDZi6KuRQHOO5TRJWgwwvZtlFfB9DpcJZVi BSgS/waeFXr8zrwEZns/9ouePB1Zlhywu5QpxxgpLO45Av+TSVwDUG9D630ifX0ed6lR GrQ1kSOj+dDiADDYISeh82iFtENUeH872A1VbhdQ/g1bwnnCvCkoFFwPrRsKzp4PaGqk D5oB9zFAmnTCZ7P9T+XgRZREbPYv+buNkuNJJiMEc5Mz5oQY/McOwiQWD8YxOT/38Lip nlDxVKH2ZK3tWp0xaB3GHzsoOnyHqT2HSCf9t9KAolMUuWEeIk/TW1eG2dGPa18wWh5x Sa7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=V10BJdzxHAV0h7gQUJltJC4aCoH9Xjs54AoTSTl4hSI=; b=LA2Uyw05P4jx3ofSQpNvzOQM2YVVG+f36wqOIg1mBDk8dqm2cZ3EmTJZlS7yt3cpLW xOiakpGNR8/5a50GrYgEzDZLe5G+ClXbfNV5kscEdgpJSB2xGJzyIph3KsWISZ/O9DmE eq4nTcvSKNUTSN4jD2Gpuf6rE773PJQF/tPZiSVG+uLLpPSynAdWD9mCTd6B9cTW1ly8 q9yZfqGYYOpdOKxBcCjxy+mFdR1fVAEkGYw45p65in129KPzfQGMNbN675pSEAYwOCnP 5dlnCk6ehqZYdL+GO27JBIsGHDL0FU8qQx9V4nTEV+7kyQl13qAsP/0OYhD2GW8Au4a/ DVaA== X-Gm-Message-State: AOAM531tXcvHGPn+oEdJSafh8ZIUkUDHkEiD4R5UsPwPCHlB+0iA2eNt 2xEk4PN9eeZaNsagqEXZL43OAQ== X-Google-Smtp-Source: ABdhPJzhRsdvQ7CU2FbitYCA1/Q8bFd4++eUf5JS+orCsOYBlsHPreE6iJfRI2xsHf65FBXuiw/VKw== X-Received: by 2002:a17:902:eb53:b029:e1:2b0f:6a88 with SMTP id i19-20020a170902eb53b02900e12b0f6a88mr1003861pli.36.1612926133001; Tue, 09 Feb 2021 19:02:13 -0800 (PST) Received: from [192.168.1.134] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id b27sm276960pgb.82.2021.02.09.19.02.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 09 Feb 2021 19:02:12 -0800 (PST) Subject: Re: INFO: task hung in io_uring_cancel_task_requests To: Pavel Begunkov , syzbot , io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk References: <00000000000075f90305baf0d732@google.com> <4ccfa4de-b63e-10c6-786a-d745cdf22535@gmail.com> From: Jens Axboe Message-ID: <563f69d6-6e93-f375-c3b9-dcb3afdae025@kernel.dk> Date: Tue, 9 Feb 2021 20:02:11 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <4ccfa4de-b63e-10c6-786a-d745cdf22535@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 2/9/21 7:57 PM, Pavel Begunkov wrote: > On 10/02/2021 00:54, syzbot wrote: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: dd86e7fa Merge tag 'pci-v5.11-fixes-2' of git://git.kernel.. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=13e43f90d00000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=e83e68d0a6aba5f6 >> dashboard link: https://syzkaller.appspot.com/bug?extid=695b03d82fa8e4901b06 >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1490f0d4d00000 >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17aedf1cd00000 >> >> IMPORTANT: if you fix the issue, please add the following tag to the commit: >> Reported-by: syzbot+695b03d82fa8e4901b06@syzkaller.appspotmail.com > > It looks like SQPOLL. I wonder if that's due to parked SQPOLL task that > won't be able to do task_work run, and so reap poll-cancelled requests > killed by io_put_deferred(). > > I'll test it out tomorrow. It is indeed SQPOLL. From a quick look, it's doing a POLL_ADD on the ring fd itself. -- Jens Axboe