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=-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 99A29C3F36E for ; Thu, 27 Feb 2020 13:49:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6913821D7E for ; Thu, 27 Feb 2020 13:49:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582811357; bh=wdqrxYPyjy0I0lxc+ygjYYNq7crfOp6Bd9hVxhogQZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SnjzIqbu8++zwc4Dxfj1V1/CR/iieGpFoq1wsCCB6Hv5mNPJpLjhlqoDzl5e4VfYG TBHSLTIsztWdiDP+s7PVIRqpNNEk2dojGw6sZsWxZYBZKw915+SzThLpVgIOvIcJs4 0pmwCPnhH7+149iYLpu8uP5nb8Ie1DRFNFddymsI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731019AbgB0NtQ (ORCPT ); Thu, 27 Feb 2020 08:49:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:46416 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730311AbgB0NtM (ORCPT ); Thu, 27 Feb 2020 08:49:12 -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 BBE9C20578; Thu, 27 Feb 2020 13:49:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582811352; bh=wdqrxYPyjy0I0lxc+ygjYYNq7crfOp6Bd9hVxhogQZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NPE9FEFkSLoQ+YhBa7ramIQm9Cuhe9fqwmAE234Fq0hbpXW+AyBc2vm7zz07YtxKb 6ELqu3JN97g8VYxpp6abndKEw3Zs2poOMxhkxfPBRbWmaFw48FU6CgIhY9ce5WFrjA cIBmAPITz32M8hWkoXCnqc9MuRop9QjJVhZO4kbE= 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 4.9 100/165] cifs: fix NULL dereference in match_prepath Date: Thu, 27 Feb 2020 14:36:14 +0100 Message-Id: <20200227132245.804081837@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132230.840899170@linuxfoundation.org> References: <20200227132230.840899170@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 751bdde6515d5..961fcb40183a4 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2927,8 +2927,10 @@ 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; -- 2.20.1