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 383FBC433EF for ; Mon, 28 Mar 2022 08:11:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239165AbiC1INR (ORCPT ); Mon, 28 Mar 2022 04:13:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234974AbiC1INR (ORCPT ); Mon, 28 Mar 2022 04:13:17 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38F91532F1; Mon, 28 Mar 2022 01:11:37 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id i11so14172181plr.1; Mon, 28 Mar 2022 01:11:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=ZMgx06IZ/vTQmKn4Nct70SDi9iZjPOBIYBwUSYQ4YmU=; b=lBMkt0MvMliAbMYT/2V+UsPfvTyN7QOaqdRD/zHSYxFwxgJ8bEoQVtBENzIZxl0LRm PZdfJ0ysFLmN7QXnCUr5qubbJF3HewyoDy7pauM9JnZLIbfoUrRDSjSJvTSSGghzJA3Z ZhX9DEoRZtE/pe19uxxqiQJ/7aY59UVm8T2yL+/HrkCWXxmVvePPWTX48xbFyVkDh1hK 151vnexDRIzdtMpspfQCYGS5KkV8fILxskGkUcO2gN98X877fU1x4QOIHrOPQQYi9/M9 2SD952WDuja8CNu82JZbxo3s+1ULNBdVXSlV+usg3GDJEISpeFt1dk5x3U8QCik6uerI OSkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=ZMgx06IZ/vTQmKn4Nct70SDi9iZjPOBIYBwUSYQ4YmU=; b=zQOEnNJofwRTPUQe1ydGDtfyVBXaK8vHpRtOCtXnPkySCB8+EyPH2tL/SvH6BvjJUy BusyUUyaRtKkVavxiA/4FWKtQ1QAzzywn2JkRpu+CFAwC3LzBgwOVEh4771apjXQD1E5 CfqdR6l0a/hRAcWQiqg5ovuGqfEImNWXrz8kp6wAptT/XRfr1MojhXDn75cX6G/Rdoye 2o97kYiKRe3pkJL781NsMo54pAmeKzNatBRcZz78qkDUwOtc+R6nbD2xm7uRuCjX8F9q o/VgzZAlIgiPeb/RgBznXS3JTycgpDmRW09ycDd9r87qBJua7cIE0Otu3lsn4/hKjguh +YVg== X-Gm-Message-State: AOAM5326EYs54AyYR4/KRkqXoK/quW4GrhKlkzpI/aEBWwC87CPIlzcW vwq7Z/Qo/v9PdjAZA0CWrPC244lKaiOAzg== X-Google-Smtp-Source: ABdhPJz1x0tEhHgEVjrXUxGt7w6IyxiYhg3FJ2bqwwNKhSEYs0f82CLytV/jgiMUz7PsgeVvjZvV8A== X-Received: by 2002:a17:90b:1d04:b0:1c7:1174:56ae with SMTP id on4-20020a17090b1d0400b001c7117456aemr39442247pjb.153.1648455096789; Mon, 28 Mar 2022 01:11:36 -0700 (PDT) Received: from ubuntu.huawei.com ([119.3.119.18]) by smtp.googlemail.com with ESMTPSA id o65-20020a17090a0a4700b001bef5cffea7sm14723754pjo.0.2022.03.28.01.11.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Mar 2022 01:11:36 -0700 (PDT) From: Xiaomeng Tong To: song@kernel.org Cc: rgoldwyn@suse.com, guoqing.jiang@linux.dev, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaomeng Tong , stable@vger.kernel.org Subject: [PATCH v2] md: fix an incorrect NULL check in sync_sbs Date: Mon, 28 Mar 2022 16:11:27 +0800 Message-Id: <20220328081127.26148-1-xiam0nd.tong@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org The bug is here: if (!rdev) The list iterator value 'rdev' will *always* be set and non-NULL by rdev_for_each(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element found. Otherwise it will bypass the NULL check and lead to invalid memory access passing the check. To fix the bug, use a new variable 'iter' as the list iterator, while using the original variable 'pdev' as a dedicated pointer to point to the found element. Cc: stable@vger.kernel.org Fixes: 2aa82191ac36c ("md-cluster: Perform a lazy update") Acked-by: Guoqing Jiang Signed-off-by: Xiaomeng Tong --- changes since v1: - rephrase the subject (Guoqing Jiang) - add Acked-by: for Guoqing Jiang v1:https://lore.kernel.org/lkml/20220327080002.11923-1-xiam0nd.tong@gmail.com/ --- drivers/md/md.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 4d38bd7dadd6..7476fc204172 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2629,14 +2629,16 @@ static void sync_sbs(struct mddev *mddev, int nospares) static bool does_sb_need_changing(struct mddev *mddev) { - struct md_rdev *rdev; + struct md_rdev *rdev = NULL, *iter; struct mdp_superblock_1 *sb; int role; /* Find a good rdev */ - rdev_for_each(rdev, mddev) - if ((rdev->raid_disk >= 0) && !test_bit(Faulty, &rdev->flags)) + rdev_for_each(iter, mddev) + if ((iter->raid_disk >= 0) && !test_bit(Faulty, &iter->flags)) { + rdev = iter; break; + } /* No good device found. */ if (!rdev) -- 2.17.1