From patchwork Fri Feb 21 07:41:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 230796 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 5D9BDC35644 for ; Fri, 21 Feb 2020 08:31:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2638920578 for ; Fri, 21 Feb 2020 08:31:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582273875; bh=cclzFkiBpLoO2SrI2jMFGiPVusooNw/Dq2xBkCYQvuQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qFKQ1vK16+3upJjeuyu6EY6G6xhAhxmZd2K6YdLA00mjeRHMRzJoK4WyKYnR8rHjH YexlnC2P1q0ipNTMOuJiR+ApG1jX1p+ERRol8mYBE34ehwG14G5Oi8aX3CmyJTf/1f CWlwQnTvELe4GQ0MP5avgkk9nSawlQsAnKTNEvCE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732798AbgBUIOZ (ORCPT ); Fri, 21 Feb 2020 03:14:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:50838 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732548AbgBUIOY (ORCPT ); Fri, 21 Feb 2020 03:14:24 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 689B720578; Fri, 21 Feb 2020 08:14:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582272863; bh=cclzFkiBpLoO2SrI2jMFGiPVusooNw/Dq2xBkCYQvuQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2fvumROBHEdYaVC/LLKL4CQZXr90vqhLhBS9StUL4jlTM/r26J6v1xQoyh9CjnoGV Dw6Udv8TWhcbx4Edfa+SsOAmtzchmnHtBzsyUBeEUHQ9YEcot1H3nIiQ0n3EKDHPlf 2YnlYuKVoe9ti2gNWnUGXNAEyNhtz3Oj3rK/vYOc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ronnie Sahlberg , Steve French , Sasha Levin Subject: [PATCH 5.4 304/344] cifs: fix NULL dereference in match_prepath Date: Fri, 21 Feb 2020 08:41:43 +0100 Message-Id: <20200221072417.533401019@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072349.335551332@linuxfoundation.org> References: <20200221072349.335551332@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ronnie Sahlberg [ Upstream commit fe1292686333d1dadaf84091f585ee903b9ddb84 ] RHBZ: 1760879 Fix an oops in match_prepath() by making sure that the prepath string is not NULL before we pass it into strcmp(). This is similar to other checks we make for example in cifs_root_iget() Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/cifs/connect.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 02451d085ddd0..5d3c867bdc808 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3652,8 +3652,10 @@ match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data) { struct cifs_sb_info *old = CIFS_SB(sb); struct cifs_sb_info *new = mnt_data->cifs_sb; - bool old_set = old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH; - bool new_set = new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH; + bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) && + old->prepath; + bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) && + new->prepath; if (old_set && new_set && !strcmp(new->prepath, old->prepath)) return 1;