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=-2.2 required=3.0 tests=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 4367CC2BA83 for ; Mon, 10 Feb 2020 01:00:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16759208C4 for ; Mon, 10 Feb 2020 01:00:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726961AbgBJBAl (ORCPT ); Sun, 9 Feb 2020 20:00:41 -0500 Received: from mail-pj1-f66.google.com ([209.85.216.66]:40577 "EHLO mail-pj1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725868AbgBJBAl (ORCPT ); Sun, 9 Feb 2020 20:00:41 -0500 Received: by mail-pj1-f66.google.com with SMTP id 12so3460649pjb.5; Sun, 09 Feb 2020 17:00:41 -0800 (PST) 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:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=n//Hlo7EBpBUMWPPN6ZGiJzHWqTb0UUf5/sr19Bi1Mg=; b=ssDItFY0RJyhvgBgoYbLmC7KYRTvlEX2+EpcQgDQu0o1MZPqFqCZGPa+TBK8oV1A2s wDBF1ytYphVdt95g09ZrgqA1kIb64SmNrfa50aEq5+X/tAwJ2LITZxOqYA2JNSmYyPg5 RWO8fXqE9kjP84QOUQEsSL9lP8yz/KeMHCmtZ9zzRNw7f8tAZeMiEERJhxK7MoIzqVuC kh5oJS4JGntN/1mV1qs7/xJi2fmM/J/j27iyrbPLSLcBXr1dwETUr10YgGY80bjsQscE 8md0+8DYsKvRyvEE13rplkDHrLj1XVgdgwgqoBB8kNTcHiNzc9CzRTC1EgObh1hnvn2E LYlw== X-Gm-Message-State: APjAAAWP8FvSwQLWL/7DQk254QhSa6dhD4BIiQI4yOJux7040aahFtm2 SLJzwZT9mQLoI40YJ47qLqs= X-Google-Smtp-Source: APXvYqzSDrKoEBbSJgTbAgeXUftY1dA1qkN/J9VXkrqbgcxUzZ10PAeq8OpMN5FcYR4LZF6lqXgPAg== X-Received: by 2002:a17:902:724a:: with SMTP id c10mr10515364pll.307.1581296440793; Sun, 09 Feb 2020 17:00:40 -0800 (PST) Received: from ?IPv6:2601:647:4000:d7:b43a:c72e:d61c:15d6? ([2601:647:4000:d7:b43a:c72e:d61c:15d6]) by smtp.gmail.com with ESMTPSA id f18sm10175072pgn.2.2020.02.09.17.00.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 09 Feb 2020 17:00:39 -0800 (PST) Subject: Re: [PATCH] block: revert pushing the final release of request_queue to a workqueue. To: yu kuai , axboe@kernel.dk, ming.lei@redhat.com, chaitanya.kulkarni@wdc.com, damien.lemoal@wdc.com, dhowells@redhat.com, asml.silence@gmail.com, ajay.joshi@wdc.com Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, zhangxiaoxu5@huawei.com, luoshijie1@huawei.com, jan kara References: <20200206111052.45356-1-yukuai3@huawei.com> From: Bart Van Assche Autocrypt: addr=bvanassche@acm.org; prefer-encrypt=mutual; keydata= mQENBFSOu4oBCADcRWxVUvkkvRmmwTwIjIJvZOu6wNm+dz5AF4z0FHW2KNZL3oheO3P8UZWr LQOrCfRcK8e/sIs2Y2D3Lg/SL7qqbMehGEYcJptu6mKkywBfoYbtBkVoJ/jQsi2H0vBiiCOy fmxMHIPcYxaJdXxrOG2UO4B60Y/BzE6OrPDT44w4cZA9DH5xialliWU447Bts8TJNa3lZKS1 AvW1ZklbvJfAJJAwzDih35LxU2fcWbmhPa7EO2DCv/LM1B10GBB/oQB5kvlq4aA2PSIWkqz4 3SI5kCPSsygD6wKnbRsvNn2mIACva6VHdm62A7xel5dJRfpQjXj2snd1F/YNoNc66UUTABEB AAG0JEJhcnQgVmFuIEFzc2NoZSA8YnZhbmFzc2NoZUBhY20ub3JnPokBOQQTAQIAIwUCVI67 igIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEHFcPTXFzhAJ8QkH/1AdXblKL65M Y1Zk1bYKnkAb4a98LxCPm/pJBilvci6boefwlBDZ2NZuuYWYgyrehMB5H+q+Kq4P0IBbTqTa jTPAANn62A6jwJ0FnCn6YaM9TZQjM1F7LoDX3v+oAkaoXuq0dQ4hnxQNu792bi6QyVdZUvKc macVFVgfK9n04mL7RzjO3f+X4midKt/s+G+IPr4DGlrq+WH27eDbpUR3aYRk8EgbgGKvQFdD CEBFJi+5ZKOArmJVBSk21RHDpqyz6Vit3rjep7c1SN8s7NhVi9cjkKmMDM7KYhXkWc10lKx2 RTkFI30rkDm4U+JpdAd2+tP3tjGf9AyGGinpzE2XY1K5AQ0EVI67igEIAKiSyd0nECrgz+H5 PcFDGYQpGDMTl8MOPCKw/F3diXPuj2eql4xSbAdbUCJzk2ETif5s3twT2ER8cUTEVOaCEUY3 eOiaFgQ+nGLx4BXqqGewikPJCe+UBjFnH1m2/IFn4T9jPZkV8xlkKmDUqMK5EV9n3eQLkn5g lco+FepTtmbkSCCjd91EfThVbNYpVQ5ZjdBCXN66CKyJDMJ85HVr5rmXG/nqriTh6cv1l1Js T7AFvvPjUPknS6d+BETMhTkbGzoyS+sywEsQAgA+BMCxBH4LvUmHYhpS+W6CiZ3ZMxjO8Hgc ++w1mLeRUvda3i4/U8wDT3SWuHcB3DWlcppECLkAEQEAAYkBHwQYAQIACQUCVI67igIbDAAK CRBxXD01xc4QCZ4dB/0QrnEasxjM0PGeXK5hcZMT9Eo998alUfn5XU0RQDYdwp6/kMEXMdmT oH0F0xB3SQ8WVSXA9rrc4EBvZruWQ+5/zjVrhhfUAx12CzL4oQ9Ro2k45daYaonKTANYG22y //x8dLe2Fv1By4SKGhmzwH87uXxbTJAUxiWIi1np0z3/RDnoVyfmfbbL1DY7zf2hYXLLzsJR mSsED/1nlJ9Oq5fALdNEPgDyPUerqHxcmIub+pF0AzJoYHK5punqpqfGmqPbjxrJLPJfHVKy goMj5DlBMoYqEgpbwdUYkH6QdizJJCur4icy8GUNbisFYABeoJ91pnD4IGei3MTdvINSZI5e Message-ID: <70ce8830-2594-2b7b-9ca9-5fb7edd374d7@acm.org> Date: Sun, 9 Feb 2020 17:00:38 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <20200206111052.45356-1-yukuai3@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2020-02-06 03:10, yu kuai wrote: > syzbot is reporting use after free bug in debugfs_remove[1]. > > This is because in request_queue, 'q->debugfs_dir' and > 'q->blk_trace->dir' could be the same dir. And in __blk_release_queue(), > blk_mq_debugfs_unregister() will remove everything inside the dir. Hi Yu, Have you already noticed patch "[PATCH] blktrace: Protect q->blk_trace with RCU"? If not, have you already tried to verify whether that patch fixes the use-after-free detected by syzbot? See also https://lore.kernel.org/linux-block/BYAPR04MB57492F689BA17786A24F08EE86190@BYAPR04MB5749.namprd04.prod.outlook.com/T/#mce8ffe534d93716f678d52178b4e34d4d1c3c597 Thanks, Bart.