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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 644CBC10DCE for ; Sun, 8 Mar 2020 16:17:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B741206D5 for ; Sun, 8 Mar 2020 16:17:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="QoHwCUSv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726340AbgCHQRi (ORCPT ); Sun, 8 Mar 2020 12:17:38 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:40690 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726279AbgCHQRi (ORCPT ); Sun, 8 Mar 2020 12:17:38 -0400 Received: by mail-pg1-f194.google.com with SMTP id t24so3578156pgj.7 for ; Sun, 08 Mar 2020 09:17:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=WCkD2GCSn4fdPzhz3uAykC3W9XDlvidafgBD2tiPQpo=; b=QoHwCUSv4rJBDXa2itzwaIu3wRYYX2GUVK9uHnslsV1YKP3XSaRMv0NfUG+PeE9K3p oHkz2NCH1gKTgAsB/GuazLIDUe6Pb5QHVZ2oB+85KOUN38qVhhFNKmfsQ8d1bjkfOsrW ougpE2ICCbm9Y/DSIyrsC0GbhTaMijJ/HVD5wDghADsvU+rtv9AcX/4k/O11IQ0MgMez 35Ip3dALn2vmKIuV5cemUp9K5V9nsZAoDbeirJFT9kl9f9KEwzcI3VJ5TVh+2P3AJDre UCnUDluEjITs1dLsFhlic/Qpvj0SkPbBiKleJZwQe3VkIYvKrB30MuA+StsLrtm7UAX+ o40A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=WCkD2GCSn4fdPzhz3uAykC3W9XDlvidafgBD2tiPQpo=; b=BAKOQdChlxOtDmZywBwy3j10gm585iFDsPPOI4mCbNSyiafFCTE+JGwD1vPLz76wAx q/iIGJ/N9K+Uk1+W3WpFHY22L0hX+BjOwE4S0QYyQWaTXXuZ8AzhVawlM9xdup3AS3oj WnQrpR+T5VCQ0i7rhs8DPT4AdAwJiqxkzcIBgdf/1EQ1eu2sVFIxzM525t5GZE4XEoLy vo4pdLSxC2spipamiLZwF57ck5cgAw5v1Xokq8o4G7j/UjSHW9R9ZO0P7haFgNb//PDv HVkZ6qO2ByPBOOhZ2GqG4OmY5C9R1jFscTq9Qf+vYlHqbyOpTGrkuPDq/WwCuAEk3sRn ozWg== X-Gm-Message-State: ANhLgQ1DRUQmHfMcbAwV0JCbgctObv+N7ca443rTwV45duZ6L6INZnL1 lgxhLpQYp7ClLz2mkCg8ZrY5yA== X-Google-Smtp-Source: ADFU+vvD6ZfzpxybygFl/1F6qmMKjdEn6yiOT7FGJmbzufWw8rlwU4yrKqONxYhhpX9EHIaEqdqWmw== X-Received: by 2002:a62:c543:: with SMTP id j64mr12936023pfg.129.1583684255347; Sun, 08 Mar 2020 09:17:35 -0700 (PDT) Received: from [192.168.1.188] ([66.219.217.145]) by smtp.gmail.com with ESMTPSA id b10sm15542888pjo.32.2020.03.08.09.17.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 08 Mar 2020 09:17:34 -0700 (PDT) Subject: Re: general protection fault in __queue_work (2) To: Hillf Danton , syzbot Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, schatzberg.dan@gmail.com, sfr@canb.auug.org.au, syzkaller-bugs@googlegroups.com References: <20200308094448.15320-1-hdanton@sina.com> From: Jens Axboe Message-ID: <407fcb3f-4380-e965-d19c-e57990711d3e@kernel.dk> Date: Sun, 8 Mar 2020 10:17:33 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200308094448.15320-1-hdanton@sina.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/8/20 3:44 AM, Hillf Danton wrote: > @@ -1208,8 +1211,16 @@ static int __loop_clr_fd(struct loop_dev > * > * 3) unlock, del_timer_sync so if timer raced it will be a no-op > */ > - loop_unprepare_queue(lo); > spin_lock_irq(&lo->lo_lock); > + do { > + struct workqueue_struct *wq = lo->workqueue; > + > + lo->workqueue = ERR_PTR(-EINVAL); > + spin_unlock_irq(&lo->lo_lock); > + destroy_workqueue(wq); > + spin_lock_irq(&lo->lo_lock); > + } while (0); This looks highly suspicious, what's the point of this loop? Also think this series a) might not be fully cooked, and b) really should have gone through the block tree. -- Jens Axboe