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=-8.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 DC603C4338F for ; Mon, 16 Aug 2021 22:52:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B481C60EE4 for ; Mon, 16 Aug 2021 22:52:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232552AbhHPWxA (ORCPT ); Mon, 16 Aug 2021 18:53:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234791AbhHPWwJ (ORCPT ); Mon, 16 Aug 2021 18:52:09 -0400 Received: from mail-wr1-x42b.google.com (mail-wr1-x42b.google.com [IPv6:2a00:1450:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78346C0617AD for ; Mon, 16 Aug 2021 15:51:36 -0700 (PDT) Received: by mail-wr1-x42b.google.com with SMTP id q10so25800270wro.2 for ; Mon, 16 Aug 2021 15:51:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=0O6fa82Nh0Fr5Z9UH6t72hdFroqOiXSZ3EmXeIatJgk=; b=battb1+KMvIqR1gWgOzzIrdyEU9VNLklzR/s1yOTBaMLZZAP6/6px82t7OaAds2+vJ Z5tLB2iZ04uutj7Mqf3ovCUDxIZvT/9PLcUSvhpwjkLIB0LvmSEyhJzHDQ8DKBLQnjJq 4Jr6cSsLf9hlGDvG4QNIz4ZJi82FkgRRuBg11ZCUmT2DFg+KdMbn/7U3TFLGNW4WSkhV ZqhZXE8bptapo+ay8jSVcKzy0bIV87SY/ESt6WSkSqVS6DBI4uaDcy0Lc3GT4f8ayIN0 di96dVBfhauQzErPK+ZDl4ShxmYE5LdLNmzBoCVdoHo++oDWOG6rV18Yg0l94ApPJj4t ix1w== 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=0O6fa82Nh0Fr5Z9UH6t72hdFroqOiXSZ3EmXeIatJgk=; b=m7r5ezSU3pZgliFm0rkzcHgFAK0o36TYkwA/TWjficmvlSc1QarrIdQxpLAOEMaGmZ BUXH5Zw9uqJ5uXufu/p6/MuC2UAmXes/ex+I62Zoj1N+EV6DG8EV8myUqKV/th8oWEYn JMLxYqKYlCaLQA3AScVS+22o28FaTZX9URm60182yF4NDW4hVRAX4zFMv32REUv2UCDt Bx+VaKUVFHpU+TlCsKEfg6kD4DS2PVSEt/XC24GBa7mCWgT0F1EBanIaQd3puXlRsGqG +dHin/JfmTPrEFvLjuM1JQa8sLU5jRU1r54GRm4eWlF7RCEtguXa9i7Ri1xj/8ETuZ1S ePMQ== X-Gm-Message-State: AOAM5325QNxfl7pYPuYpLzVI25isOGRmd4jdGKkCv5dNNp3AoXb7BTX1 koiKkd9t3ktkGdvfuttSA6U= X-Google-Smtp-Source: ABdhPJwyafgf7ruq++vian04cSdG5biEQnz/hQiGVFLI3N4LYJFWLsHCbNqzV7C/zSxH+4eBn7axeA== X-Received: by 2002:a5d:674b:: with SMTP id l11mr350885wrw.357.1629154295140; Mon, 16 Aug 2021 15:51:35 -0700 (PDT) Received: from [192.168.8.197] ([85.255.233.12]) by smtp.gmail.com with ESMTPSA id e3sm188088wrv.65.2021.08.16.15.51.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 16 Aug 2021 15:51:34 -0700 (PDT) Subject: Re: [PATCH 5.15] io_uring: don't forget to clear REQ_F_ARM_LTIMEOUT To: Jens Axboe , io-uring@vger.kernel.org Cc: syzbot+2b85e9379c34945fe38f@syzkaller.appspotmail.com References: <614f650abdd5fee97aa5a6a87028a2c47d2a6c94.1629137586.git.asml.silence@gmail.com> <16575c24-51d9-0946-4a89-d4320b51d79b@kernel.dk> From: Pavel Begunkov Message-ID: <6e155bdb-1a75-f415-4eb2-db543e3b2625@gmail.com> Date: Mon, 16 Aug 2021 23:51:04 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <16575c24-51d9-0946-4a89-d4320b51d79b@kernel.dk> 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 8/16/21 7:49 PM, Jens Axboe wrote: > On 8/16/21 12:16 PM, Pavel Begunkov wrote: >> Even though it should be safe to poke into req->link after >> io_issue_sqe() in terms of races, it may end up retiring a request, e.g. >> when someone calls io_req_complete(). It'll be placed into an internal >> request cache, so the memory would be valid with other guarantees, but >> the request will be actually dismantled and with requests linked removed >> and enqueued. >> >> Hence, don't forget to remove REQ_F_ARM_LTIMEOUT after a linked timeout >> got disarmed, otherwise following io_prep_linked_timeout() will expect >> req->link to be not-zero and so fault. > > Since its tip of tree, I will just fold this one in. Perfect, thanks! -- Pavel Begunkov