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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6CC9FC7618B for ; Wed, 24 Jul 2019 09:08:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3963921951 for ; Wed, 24 Jul 2019 09:08:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="V7bJdNy/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726763AbfGXJIq (ORCPT ); Wed, 24 Jul 2019 05:08:46 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:42112 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725999AbfGXJIp (ORCPT ); Wed, 24 Jul 2019 05:08:45 -0400 Received: by mail-pf1-f196.google.com with SMTP id q10so20609288pff.9 for ; Wed, 24 Jul 2019 02:08:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=09CsS3ko6lzH/0V10YXQF8pRitb7C2CLQvJO5AREnSE=; b=V7bJdNy/iE/nCZXfk/Q/TCnAA34debDwTZZ1M4YDyiNLF6A5FE9wxdfYAvxN6rgiVO IUBynba+yRV/n7ePvcmhmYOj/PbxbakbGXO0zye+0AMCIuUhyR3U45Mb2hl9bZoZclvz MTWSfkANhFigy7uwXG6B7jzYuOOGYJY2zJjoXWokPFeZx9kcHyyfvXcNWCGk3T8iyNja Q/qoqYD1WhvhAe5ZM56ROmssx+3m3ifSr+VMYzqR6VNHVAIwh6wd6ZTdLv82y3Fgzwjb so/cAlhL1qfgy6MUqcEilF2uRZmFj1ybyonnqxcIdSizWUx7/szxnh71u9Y6m9MF/cjd INTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=09CsS3ko6lzH/0V10YXQF8pRitb7C2CLQvJO5AREnSE=; b=FoYJwHZhHljkifcyeCb2e3UMVyPByPxJ3b4pOjBHvCCzJ4pLRJAMRXCG6sJWy7WEbo Cq0/nXEg7mTCS0M5s5pZV/n6EEsnL9iSx8nseIcNnP6fP/o70zB2cQcV96HXx6X07+g4 qdjWw9GEM0+Gmk+LF7EA94kAn6+jvd5an21gD2UDqobWMawJjREm2fnrJkUevZx8f5PC eHJvjGLSjaRdfcEeQYEPW793zx0Koib4c7hZmPVycN6GW3zGhR2Q++58L1wdnIDjJTaA a7f09HDjZgUkulkoqE9KTj227fYja+LELyKb2QmwjN7hSDUrVSDklfiQcB/yPcWy/7k1 M0ug== X-Gm-Message-State: APjAAAXfqyJkaSgbui3nsS2O0JglnQ7GPPM+lq2gkJKx/L6ZQB1qJzLS 18j7ps8pbxycTrDiDpuridkeMQaCsd8= X-Google-Smtp-Source: APXvYqxa+oNYmupFnZcbNaTroSq3yDCbTnIojD2SeB7FIypF8xyOhbA+keos0ryT6Z1Fyf/gaoZljQ== X-Received: by 2002:a62:79c2:: with SMTP id u185mr10440507pfc.237.1563959325044; Wed, 24 Jul 2019 02:08:45 -0700 (PDT) Received: from ?IPv6:2402:f000:4:72:808::177e? ([2402:f000:4:72:808::177e]) by smtp.gmail.com with ESMTPSA id o14sm93701300pfh.153.2019.07.24.02.08.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Jul 2019 02:08:44 -0700 (PDT) Subject: Re: [Cluster-devel] [BUG] fs: gfs2: possible null-pointer dereferences in gfs2_rgrp_bh_get() To: Steven Whitehouse , rpeterso@redhat.com, agruenba@redhat.com Cc: cluster-devel@redhat.com, linux-kernel@vger.kernel.org References: <8d270882-54da-365e-1be7-a291a5178b1e@gmail.com> From: Jia-Ju Bai Message-ID: <48547b12-ee4c-4f8c-d004-925d65f672d8@gmail.com> Date: Wed, 24 Jul 2019 17:08:47 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for the reply :) On 2019/7/24 17:04, Steven Whitehouse wrote: > Hi, > > On 24/07/2019 09:50, Jia-Ju Bai wrote: >> In gfs2_rgrp_bh_get, there is an if statement on line 1191 to check >> whether "rgd->rd_bits[0].bi_bh" is NULL. > > That is how we detect whether the rgrp has already been read in, so > the function is skipped in the case that we've already read in the rgrp. > > >> When "rgd->rd_bits[0].bi_bh" is NULL, it is used on line 1216: >>     gfs2_rgrp_in(rgd, (rgd->rd_bits[0].bi_bh)->b_data); > > No it isn't. See line 1196 where bi_bh is set, and where we also bail > out (line 1198) in case it has not been set. > I overlooked the operation on line 1196... Thanks for the pointer, I am sorry for the false report... Best wishes, Jia-Ju Bai