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 ECC0AC433F5 for ; Fri, 7 Jan 2022 15:00:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347951AbiAGPAv (ORCPT ); Fri, 7 Jan 2022 10:00:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347948AbiAGPAu (ORCPT ); Fri, 7 Jan 2022 10:00:50 -0500 Received: from mail-yb1-xb34.google.com (mail-yb1-xb34.google.com [IPv6:2607:f8b0:4864:20::b34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B512AC061574; Fri, 7 Jan 2022 07:00:50 -0800 (PST) Received: by mail-yb1-xb34.google.com with SMTP id y130so17422488ybe.8; Fri, 07 Jan 2022 07:00:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:from:date:message-id:subject:to:cc; bh=zBP2UiF21UFw2eESSHmBXsLTbX6dsMz14iTZzwr956s=; b=IlbJ4ap/sZZsQIwZlAl1lMs5jHWkMxQGF1Ko4cquETHIAGml1rPCAn2/bhJ8CSqrhU 81sHiXmjkfhv3IvxQhpYGvqtUB4GqJyiukyNePOz95O2INrvBD+xTGhKdEyx4cKrN1FS Xjiw2YbQJnha1b5zYORXiLP4kNjkHWwtDXkIIFieBZJ8V3IIaqNH4bnzMz164VMNO47n UhSK9iyGfS03MdDOnDeXn4lrcXXbwQc9gr3YPtSGikOH3OuANt4quh3j8uUC6c0vlkX5 jaHE6HRTlf5vVxy9IkTHutkQ8VV7kiP5ZeSKNhVtDf8TXdfCWOuXsx771PpqOerXPMvu boEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=zBP2UiF21UFw2eESSHmBXsLTbX6dsMz14iTZzwr956s=; b=1QfkAhcRL66NF6rXE9OnAsFyovTaceTj1WcVJCFPE6uPmuoXn4GxATymulFxGzmQv7 Q6cVlR0qWXrh+mL+R1ZoXd/dYUP7OgRMH1EF8X1iURpQJy5kMlh7rCy9gPleYhvf6yoe RWPO3irZd8axls691zH8uCB+QMcFnY2UYPLeWJ+kucdxe3WhjM5TjuT3gjR6ZHrRZL6u vTvWj96H+W47EjDb3tPuRBMyRPofleZtc6P0LcKmW1CJwM0rLshcsGGgxz9r+oOOp5cM iTchVEvHR1tN5Vo+wQsZ90YoHpS1awbrvuAu/FcVzNK/qdISOOG+1opBPSk/CVVbPca0 iL1g== X-Gm-Message-State: AOAM532F353K/IrXZVRegui5+CS7H6pycGunJTew3Sy8YjkUlQI+i68j OqILiTWfgnGuD7gpU3X/Z4Ivaf7j0AJ56wIPnwQFjZBoonw= X-Google-Smtp-Source: ABdhPJz3k7QzMxTOfHoyGZtOuExUCU4D18eWUERoGbJWm01EdLQlvhmuola1tIB7FAwEZJ7SlnijbWS/UFVqNUgOV9I= X-Received: by 2002:a25:500f:: with SMTP id e15mr78539623ybb.312.1641567649858; Fri, 07 Jan 2022 07:00:49 -0800 (PST) MIME-Version: 1.0 From: Lukas Bulwahn Date: Fri, 7 Jan 2022 16:00:39 +0100 Message-ID: Subject: Observation of a memory leak with commit e98e49b2bbf7 ("io_uring: extend task put optimisations") To: Pavel Begunkov , Jens Axboe Cc: Linux Kernel Mailing List , io-uring@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 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. Best regards, Lukas