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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 55BE4C43461 for ; Mon, 14 Sep 2020 09:18:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2270E2192A for ; Mon, 14 Sep 2020 09:18:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726280AbgINJSs (ORCPT ); Mon, 14 Sep 2020 05:18:48 -0400 Received: from mx2.suse.de ([195.135.220.15]:54652 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726123AbgINJSr (ORCPT ); Mon, 14 Sep 2020 05:18:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B9090ADC2; Mon, 14 Sep 2020 09:19:00 +0000 (UTC) Date: Mon, 14 Sep 2020 11:18:44 +0200 From: Michal Hocko To: Muchun Song Cc: Andrew Morton , Johannes Weiner , Vladimir Davydov , Cgroups , Linux Memory Management List , LKML Subject: Re: [External] Re: [PATCH] mm: memcontrol: Fix out-of-bounds on the buf returned by memory_stat_format Message-ID: <20200914091844.GE16999@dhcp22.suse.cz> References: <20200912155100.25578-1-songmuchun@bytedance.com> <20200912174241.eeaa771755915f27babf9322@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 14-09-20 12:02:33, Muchun Song wrote: > On Sun, Sep 13, 2020 at 8:42 AM Andrew Morton wrote: > > > > On Sat, 12 Sep 2020 23:51:00 +0800 Muchun Song wrote: > > > > > The memory_stat_format() returns a format string, but the return buf > > > may not including the trailing '\0'. So the users may read the buf > > > out of bounds. > > > > That sounds serious. Is a cc:stable appropriate? > > > > Yeah, I think we should cc:stable. Is this a real problem? The buffer should contain 36 lines which makes it more than 100B per line. I strongly suspect we are not able to use that storage up. -- Michal Hocko SUSE Labs