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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 83C5BC432BE for ; Thu, 19 Aug 2021 20:57:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E08761029 for ; Thu, 19 Aug 2021 20:57:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235364AbhHSU5i (ORCPT ); Thu, 19 Aug 2021 16:57:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230031AbhHSU5h (ORCPT ); Thu, 19 Aug 2021 16:57:37 -0400 Received: from mail-wm1-x32d.google.com (mail-wm1-x32d.google.com [IPv6:2a00:1450:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8B40C061575; Thu, 19 Aug 2021 13:57:00 -0700 (PDT) Received: by mail-wm1-x32d.google.com with SMTP id w21-20020a7bc1150000b02902e69ba66ce6so4773865wmi.1; Thu, 19 Aug 2021 13:57:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:references:from:subject:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=K7z0p/jibmo9XkKs22cylHJSL1ZQYrlcqLELAzZjuMM=; b=eG8JoX8cndeEjZrNzSeCF9Yr7JodOqglZAT3PGzsDKW1+J/EKI/Q/Sa3L50l3VNvd7 UkGKia59VUOAuwxuxnhnU14+b8sJFdGTxXQNHHl2U3f4jwTDFvLBASb1Uy6Yfh7JA1nB 6vKk9InSmR6xXJ2lt8n1+NJycdPF46OTuxsKBNxR+QolBCMuEMhwbn43U4h78h70vhJk zz0S36vgpPwfwhOkwinMpBjPKpEXpT1awivQoOJPDVgOl9Eo6ERhkl/4j1Wimo9toqRn oYSHQ3ydPnvtH/BA1g4fvK/fsTw72FN1JO+rKl//hIBqc6cEua9u9jcUNNmqBCb/+Hu3 qPOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:references:from:subject:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=K7z0p/jibmo9XkKs22cylHJSL1ZQYrlcqLELAzZjuMM=; b=SbQInj+DExT5FZzUJ/WxPzMTkXbaOwTlT9F6jpcWx21PF2jBkuTy92Oo55lsNmdP9D SeO5KRwPTNQt9nnZq8AexyV8VMVkwhXkuMuPBUqJjZTdD17oWKLyb/yagr+Arg1IvAZ+ T3u+mOIuSSOVEq4SnQvg0YQ+BwbttFnEWDPmV6vDQpfR0D70XUQGhthgY6eaRLDQ16J7 lBh8K0himWTavBq2IensLXQkz/W20wOn/XqkFyvYg8+Dn/LE7RPwocKmHzTv396aJw1e NzcL1pI2l23YH5LPq7KcapWcAHBWLEbIkH2bN5sYjAPc6VCLaQpD4dDnJJ1lUzGsQj7x gyzQ== X-Gm-Message-State: AOAM5336RLB2kar8cHiNo/R7sXWfbt7xEtS//0dCUhSV6+qUJrp5Wwzp j9lQW+H8TSrUlKOT8BEI93g= X-Google-Smtp-Source: ABdhPJxPtnJFYPoOAx0Ck1vv6n8nnYvS44YlYZUlqOMnqmmsm9eSdYJ+KdF4j19HAIP8kjtwmsutQg== X-Received: by 2002:a05:600c:4896:: with SMTP id j22mr498385wmp.170.1629406619431; Thu, 19 Aug 2021 13:56:59 -0700 (PDT) Received: from [192.168.8.197] ([185.69.145.21]) by smtp.gmail.com with ESMTPSA id s10sm4672972wrv.54.2021.08.19.13.56.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 19 Aug 2021 13:56:59 -0700 (PDT) To: syzbot , axboe@kernel.dk, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com References: <00000000000008f3c605c9ecd545@google.com> From: Pavel Begunkov Subject: Re: [syzbot] KASAN: use-after-free Read in tctx_task_work (2) Message-ID: Date: Thu, 19 Aug 2021 21:56:28 +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: <00000000000008f3c605c9ecd545@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/19/21 6:25 PM, syzbot wrote: > Hello, > > syzbot has tested the proposed patch and the reproducer did not trigger any issue https://git.kernel.dk/cgit/linux-block/commit/?h=for-5.15/io_uring&id=84a8ffdcd42da1f0710819e863a7db4309d4ceac Ok, looks this patch broke it. I need to look where I'm wrong, but for now it should be dropped. > > Reported-and-tested-by: syzbot+9c3492b27d10dc49ffa6@syzkaller.appspotmail.com > > Tested on: > > commit: 923ffe35 Revert "io_uring: improve tctx_task_work() ct.. > git tree: https://github.com/isilence/linux.git syztest_ctx_tw > kernel config: https://syzkaller.appspot.com/x/.config?x=cb4282936412304f > dashboard link: https://syzkaller.appspot.com/bug?extid=9c3492b27d10dc49ffa6 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 > > Note: testing is done by a robot and is best-effort only. > -- Pavel Begunkov