From patchwork Sun Mar 27 05:37:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiaomeng Tong X-Patchwork-Id: 554972 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 42AB8C433F5 for ; Sun, 27 Mar 2022 05:37:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233643AbiC0Fj1 (ORCPT ); Sun, 27 Mar 2022 01:39:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233298AbiC0Fj0 (ORCPT ); Sun, 27 Mar 2022 01:39:26 -0400 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C68674755A; Sat, 26 Mar 2022 22:37:48 -0700 (PDT) Received: by mail-pf1-x42b.google.com with SMTP id p8so9823789pfh.8; Sat, 26 Mar 2022 22:37:48 -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=YdydescwhQudHUcMwcRf7BOVetd8YMQuuJ2ndUf+Dc0=; b=h/ysz42WxXShL9BRdP/kaK0ZKZI88YC4SRzum9sxEiJcOW/V6Jqv0/3aGObuV4w2xs 4k4dA35NpaCni+GjEycdibOQpNZqmAW+/dSk01GwanXZUfywg3aGuBek+YvIWLzyYWB1 n17J8Q1WfcborxHi5U9OW79XK/r7l96OWQMyyy4m6UTvUlSDxNyy61rWhdgSvJKRePha oP5LGcgjnoN9tm8rJTMlOOo/AQWn7yFOA+cpYmPM0lSqU7OpzWIIfzDCbjeN8HI20XmE /IzfHlVzxm1YoJ6U20iCFFeTpYwmB0N2BvROPFtQrc5w6gYSlTB3KhRxTxWpla9UIgp6 a4eQ== 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=YdydescwhQudHUcMwcRf7BOVetd8YMQuuJ2ndUf+Dc0=; b=NDqPGdxd+Lmz7WSlp7ee5WuOl1Pel3arzydKuaJSAYbaRTtN4BJqpwZiltuRXsfk2M xStJi7w+WeCC1dl7L+8O3f6e9SBTUlCkBQIcWerz67zcgrFlavrL/3pPBUgwl0LOkSyw jxY8fLOurTAkrwDtLiTHvDrG+KNuygwa0OIi01wFsWnNwk3mR9DlhIP2Tbe3/L/IiVqk CdcGji27auis6zQQ/L7MsauAE4Iqjg738tjut3gRlj2MnEGb+VFUQOS1ItqEm1BrQeO/ I/Iwx2Qqu+KHKEdpAwG3D4ru1xtLb96io4a+5Pn552V8Iu1i7tlqrG3SjHvIFQWshI/N CsZQ== X-Gm-Message-State: AOAM532TEX3BuGOWtY4AZq+knpWXyknRAMO+h0ptaHjJXREOjAIaFZ9r mye39CAWk6DRQa/oSEkxQz8= X-Google-Smtp-Source: ABdhPJyubYND3HSZH+Hz7/ildaeL/ooFKUO4nknydTh1SQSem3kX+BM8Ua6O0vUakkfuejmn6Jxa8w== X-Received: by 2002:a63:2004:0:b0:375:ed63:ab4c with SMTP id g4-20020a632004000000b00375ed63ab4cmr5706231pgg.255.1648359468193; Sat, 26 Mar 2022 22:37:48 -0700 (PDT) Received: from localhost.localdomain ([115.220.243.108]) by smtp.googlemail.com with ESMTPSA id j14-20020a056a00174e00b004fb100a1b51sm7645394pfc.94.2022.03.26.22.37.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 26 Mar 2022 22:37:47 -0700 (PDT) From: Xiaomeng Tong To: agk@redhat.com Cc: snitzer@redhat.com, dm-devel@redhat.com, linux-kernel@vger.kernel.org, Xiaomeng Tong , stable@vger.kernel.org Subject: [PATCH] md: fix missing check on list iterator Date: Sun, 27 Mar 2022 13:37:42 +0800 Message-Id: <20220327053742.2942-1-xiam0nd.tong@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The bug is here: bypass_pg(m, pg, bypassed); The list iterator 'pg' will point to a bogus position containing HEAD if the list is empty or no element is found. This case must be checked before any use of the iterator, otherwise it will lead to a invalid memory access. To fix this bug, run bypass_pg(m, pg, bypassed); and return 0 when found, otherwise return -EINVAL. Cc: stable@vger.kernel.org Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xiaomeng Tong --- drivers/md/dm-mpath.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index f4719b65e5e3..6ba8f1133564 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -1496,12 +1496,13 @@ static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed) } list_for_each_entry(pg, &m->priority_groups, list) { - if (!--pgnum) - break; + if (!--pgnum) { + bypass_pg(m, pg, bypassed); + return 0; + } } - bypass_pg(m, pg, bypassed); - return 0; + return -EINVAL; } /*