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=-5.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 94015C433DF for ; Wed, 5 Aug 2020 19:14:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BAFE20842 for ; Wed, 5 Aug 2020 19:14:51 +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="BZyj8tQZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729037AbgHETOu (ORCPT ); Wed, 5 Aug 2020 15:14:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727066AbgHETMp (ORCPT ); Wed, 5 Aug 2020 15:12:45 -0400 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85711C0611E0 for ; Wed, 5 Aug 2020 12:10:56 -0700 (PDT) Received: by mail-pl1-x643.google.com with SMTP id k13so18104424plk.13 for ; Wed, 05 Aug 2020 12:10:56 -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=/BPxTQP7JYvXtVQk0ki81teqlb2JaRXEp1ARBXZnsKo=; b=BZyj8tQZ0jh5Oos+bACAQdHzM8BctEVB1nm/RUpKxUQ6Pi6G9SvTFeD7fBZ/X6lfVI FkEJ/WjkqHZlKv6fs1JF+djzVBcU9No5gkz3vxU0yeAYZg6d4i9kwLBmPh3V4BN9RclB zTSxsjl5UmQZ3wGmv+ar3sNRei7z2zx0aTBPLAJrM8lq2oHQ27xaltidycvB+G9bYUaR iPPkoe5114KZNWhvTOaH3rhFgeMCltmUtlYFwAd/c5ctZi1gdsQ0E0v/X7k+i7g+xyTm JUxqfiNWjVM174YYeHWS7YFZ5kytejVTaFOyGZHdu4NYhmfkoZnYnf3xaO34Fv5Opblj Nqmg== 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=/BPxTQP7JYvXtVQk0ki81teqlb2JaRXEp1ARBXZnsKo=; b=nbIiSRJNNQi8WwW52gAbmLVSZ4Y99WIWSZt5ugNnS12fYvG8tGnNaspWQEmoHRYvaE uEMMexe8q15fnRsA/ozfeyvL4cAZIzF/CA5FfEu7AxJAA8XeYSSz6YeKEYqianrMXAet bxFCwI50dlCFgYb4AD67fqTJTIdrCTxm9hAwn2pg/litClXsGccluUMjAke2Aj35c7Dl vPxflvn7idjSv6agVlFwIkJWgMNDYfMHHtQv4cWy/DNVErcFh9JtAIM6kM/+fy+7tkCd hx8Jxz6cg2SwH+nz07PAXhepR94JuQZTZA3HrWUh7EXj4YeWhUB2jw+iLy0gj6wVA3uJ +Lng== X-Gm-Message-State: AOAM530alCsnqEWiioPJG75gLm/RFLCf7Mk/SI+NCCubCaGq1g19Z80n VUNjc6sPpAA5e8MIL1RYjrj0aPsjrbQ= X-Google-Smtp-Source: ABdhPJxBxqd+46Ue4ysKapAHTBKv3UWlsAyzGfbE/liq0Ut6moG79tcjnHZxH6I+Zn1xfkVM57hEQA== X-Received: by 2002:a17:90a:77ca:: with SMTP id e10mr4434931pjs.150.1596654655824; Wed, 05 Aug 2020 12:10:55 -0700 (PDT) Received: from [192.168.1.58] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id s125sm5061242pfc.63.2020.08.05.12.10.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 05 Aug 2020 12:10:55 -0700 (PDT) Subject: Re: [PATCH] io_uring: Fix use-after-free in io_sq_wq_submit_work() To: Guoyu Huang , viro@zeniv.linux.org.uk Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200805034042.GA29805@ubuntu> From: Jens Axboe Message-ID: Date: Wed, 5 Aug 2020 13:10:54 -0600 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: <20200805034042.GA29805@ubuntu> 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 8/4/20 9:40 PM, Guoyu Huang wrote: > when ctx->sqo_mm is zero, io_sq_wq_submit_work() frees 'req' > without deleting it from 'task_list'. After that, 'req' is > accessed in io_ring_ctx_wait_and_kill() which lead to > a use-after-free. This looks like an old one, that affects 5.4 only. I've massaged it to apply on top of another fix, will ask to get it queued up for stable. Thanks! -- Jens Axboe