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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72198C433F5 for ; Sun, 9 Jan 2022 00:58:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235051AbiAIA6D (ORCPT ); Sat, 8 Jan 2022 19:58:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235048AbiAIA6D (ORCPT ); Sat, 8 Jan 2022 19:58:03 -0500 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07B72C06173F; Sat, 8 Jan 2022 16:58:03 -0800 (PST) Received: by mail-wr1-x42e.google.com with SMTP id k30so1608937wrd.9; Sat, 08 Jan 2022 16:58:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language :from:to:cc:references:in-reply-to:content-transfer-encoding; bh=aEpu3o18b3C+mPQjgIJSZna8gX09G1civRUAdCthvY8=; b=MMUp06bThKCsrELvgNFXBuaxlTutT5d7THW8qjnHcG/Kh9kGDyVHSF7Va6NGxFqFys tJ+GYgcB4jN8DXBMPxaib9avJtZu52/vE57YVLHb10LpKVXkIqAj4gf9J5qg4C+VScxQ Ct13H91nDu61OiWwwMZGjP1kiW7vuuvQQsSXtdlhgF5zey9jgIo/Q40/ag9pTBo742eT bkr6aiZYXpQCBBYVpErkt20GKyAJ0a1ny5jJcySrfMXPTLAyqOUpl+T0p2OlOaLR4Nt5 OL2wvJ0YNzzkEdwYbpXTzeRIKHO/NPGpW7mZCSRy9gvrn3rAALlx6MG3jPyRk2XO/vIW BxlA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:from:to:cc:references:in-reply-to :content-transfer-encoding; bh=aEpu3o18b3C+mPQjgIJSZna8gX09G1civRUAdCthvY8=; b=Jk+hwF8eeZqXfEbJxWBrH8xxLPhW5eKGe6e+DNol4ajsjC3OzcsromO1ZHupvezWI2 wrtvdYvNTwXevXuzSWTMt+aAG6s8TcTyyjjr8sdXuYEfauxeG3aY+v+Y+4VJsCsxpQcD XPnkjaFmDGiGvIU64v7Y9tDIcLOgQ+xBPXbEr98nJjEfYTvZrw0kZmzBLnahdrpFFX5u 8iPEDcw5b0y27OelIgAVCdMvaE03Bk7pN/tyqBseDPmLoy5uxRRCqxgNw0FStywGI9+X yY3bwvipZHjmfT7l0ixKIb8ElpO1xkJIVcWnxjq5ux0cFVEjmELhjRXfr4fDPbBVx4IN wgcA== X-Gm-Message-State: AOAM531G6wQ5obdDSX59q1a/JgjIXmJJrDzqlkHIH8ODsWtI+KZZj2H/ bcNVpJ5n/3YDRO6CYwD6yK3Tn+0wu4w= X-Google-Smtp-Source: ABdhPJxkjaZnfUetLtNYPS20H2eVunOsEDTlWwg8W62dTL6nAFqpA5hThJJra2ux/pAeUzwGCwHxLg== X-Received: by 2002:a05:6000:1aca:: with SMTP id i10mr58901930wry.453.1641689880787; Sat, 08 Jan 2022 16:58:00 -0800 (PST) Received: from [192.168.8.197] ([185.69.144.215]) by smtp.gmail.com with ESMTPSA id n12sm3124335wrf.29.2022.01.08.16.58.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 08 Jan 2022 16:58:00 -0800 (PST) Message-ID: <5f2be3fe-7a16-6559-7d40-575c6e29e443@gmail.com> Date: Sun, 9 Jan 2022 00:57:15 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: Observation of a memory leak with commit e98e49b2bbf7 ("io_uring: extend task put optimisations") Content-Language: en-US From: Pavel Begunkov To: Lukas Bulwahn , Jens Axboe Cc: Linux Kernel Mailing List , io-uring@vger.kernel.org References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 1/7/22 16:22, Pavel Begunkov wrote: > On 1/7/22 15:00, Lukas Bulwahn wrote: >> Dear Pavel, dear Jens, >> >> In our syzkaller instance running on linux-next, >> https://elisa-builder-00.iol.unh.edu/syzkaller-next/, we have been >> observing a memory leak in copy_process for quite some time. >> >> It is reproducible on v5.15-rc1, v5.15, v5.16-rc8 and next-20220106: >> >> https://elisa-builder-00.iol.unh.edu/syzkaller-next/crash?id=1169da08a3e72457301987b70bcce62f0f49bdbb >> >> So, it is in mainline, was released and has not been fixed in linux-next yet. >> >> As syzkaller also provides a reproducer, we bisected this memory leak >> to be introduced with commit e98e49b2bbf7 ("io_uring: extend task put >> optimisations"). >> >> Could you please have a look how your commit introduces this memory >> leak? We will gladly support testing your fix in case help is needed. > > Thanks for letting know > I think I know what it is, will get back later. https://lore.kernel.org/io-uring/69f226b35fbdb996ab799a8bbc1c06bf634ccec1.1641688805.git.asml.silence@gmail.com Should fix it, tested with the repro -- Pavel Begunkov