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=-5.8 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham 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 58047C43382 for ; Fri, 28 Sep 2018 11:35:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 09FB321547 for ; Fri, 28 Sep 2018 11:35:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=toxicpanda-com.20150623.gappssmtp.com header.i=@toxicpanda-com.20150623.gappssmtp.com header.b="b4ZSXKT6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09FB321547 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=toxicpanda.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729502AbeI1R7L (ORCPT ); Fri, 28 Sep 2018 13:59:11 -0400 Received: from mail-qt1-f194.google.com ([209.85.160.194]:39663 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729232AbeI1R7L (ORCPT ); Fri, 28 Sep 2018 13:59:11 -0400 Received: by mail-qt1-f194.google.com with SMTP id c25-v6so6192713qtp.6 for ; Fri, 28 Sep 2018 04:35:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=zRPAcBZ0jXExz0b9Z/2xy54NjiQ4uqpuPp/PL1Sdyig=; b=b4ZSXKT6F2jUh2N/0+0f6amJx8k2m1O5JtT77YQ7ndzKzALwp8nwiLjkht1KzsLmNJ thVrca3Y2SVtQ6zK0fKryDP/yTToKNa1ndHX3x4ISz8rSPsWchMUFd5AItMpLME3DQEn fGykCCt46WE37QDcIcdHs0GxU9GgVMolER9ZDP2qoue7Lj6m1mWRmofOBvBX0YqU/vp6 r/6/K0QD1ZwGa+WGksCWNTvlsNCQpraLKEb4sE6ucvDN1v47A9OVmN+pkwDwxFmncPND 0RhhWT9fQYUmSXXA7gxkNFyOcLioXqBI4r0Q8vh0UazsWo34vX6ukOA1LXQx/GhFQDYU cQ4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=zRPAcBZ0jXExz0b9Z/2xy54NjiQ4uqpuPp/PL1Sdyig=; b=ghc6TG7+NGyvJohwsDzhOz0Ywa/ncmNu61Yj4SDdP8e5+NHXeZXofJIcYtx6JevfNH xi0NML4oBXsFpbNPB/a2QH8Yw/4oznWWWvChB76b+2N8nRH8ep4XO/VMGJ+cVhkyhzQW d5VkXgJ1cEyhNbBJ4xqiekPnE3UuJZ/R+gNzSYyh+MaSDim4gLPo/Q4WpqPg8rJepxEw XO5TfLMNUgSNBkbFHS30xfgnqqFP6C+AKBmm3a5kI2CZzmoVokt5tZpTBSfBrTIIz962 25qfr7/SzmIYUu0I/6IIyIhtj/OGSOTr1o5tO4wSF4uPXMFPy9eBnmlbUau1Sqey5Zf1 EQzA== X-Gm-Message-State: ABuFfogDFF5cNaOeo7MZWV1gfH9LojdFlu38/8L0rxz/5f7x/f4b2t2a RP9tqL6MLoFoSlMNfLQ+2CcGWQ== X-Google-Smtp-Source: ACcGV61tp02EO4UDQfPkGeza6oT1sCB5D/EO9RIUeXywL6mFfbBiTPTWHJ/v1z4qAMf1/gKsh9KtTg== X-Received: by 2002:a0c:8748:: with SMTP id 8-v6mr11630332qvi.223.1538134549862; Fri, 28 Sep 2018 04:35:49 -0700 (PDT) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id i14-v6sm2991116qta.53.2018.09.28.04.35.48 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 28 Sep 2018 04:35:48 -0700 (PDT) Date: Fri, 28 Sep 2018 07:35:48 -0400 From: Josef Bacik To: Kirill Tkhai Cc: akpm@linux-foundation.org, gorcunov@openvz.org, mhocko@suse.com, aryabinin@virtuozzo.com, hannes@cmpxchg.org, penguin-kernel@I-love.SAKURA.ne.jp, shakeelb@google.com, jbacik@fb.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: Fix int overflow in callers of do_shrink_slab() Message-ID: <20180928113546.sc7cztwsja4advli@destiny> References: <153813407177.17544.14888305435570723973.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153813407177.17544.14888305435570723973.stgit@localhost.localdomain> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 28, 2018 at 02:28:32PM +0300, Kirill Tkhai wrote: > do_shrink_slab() returns unsigned long value, and > the placing into int variable cuts high bytes off. > Then we compare ret and 0xfffffffe (since SHRINK_EMPTY > is converted to ret type). > > Thus, big number of objects returned by do_shrink_slab() > may be interpreted as SHRINK_EMPTY, if low bytes of > their value are equal to 0xfffffffe. Fix that > by declaration ret as unsigned long in these functions. > > Reported-by: Cyrill Gorcunov > Signed-off-by: Kirill Tkhai Reviewed-by: Josef Bacik Thanks, Josef