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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 CB4C9C43381 for ; Wed, 27 Mar 2019 18:32:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 946F4204FD for ; Wed, 27 Mar 2019 18:32:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553711531; bh=N2/r+LM+NJ1f3JmOsTRyGvXbjDxj+ST7Ee+qWE0CXik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TDVSbbFBd4kc+4bsRTLC3e9ntyUyiA7YfLZhvoa+H8ewBGHSdDblK9slMkFeRCOhN WqB5BJNGVfvsJx3sKS+6NVqT0F96aBkahYJJq/od+2bUKa66t7NjDvaPszyR4WhxZ1 7B5P2ViVn4sM3nf2SUDCbcH+d2aU1s0Oe3558T9w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391931AbfC0ScK (ORCPT ); Wed, 27 Mar 2019 14:32:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:45018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391620AbfC0SZj (ORCPT ); Wed, 27 Mar 2019 14:25:39 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 733912184C; Wed, 27 Mar 2019 18:25:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553711139; bh=N2/r+LM+NJ1f3JmOsTRyGvXbjDxj+ST7Ee+qWE0CXik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bWqlv516Irpij6xASr4a2D6rZBF2Dla6drjYRvPUm+WrKUW18FS1wg+9exmwbiaL6 XhIwK/TOx1nNdQ7RH03b4Dgc2DlhiH9rG3RPYhgriVjEgVueke+hsdDuj/xBYsDk1u pnmnnueL37/TKQfKmxjkVSapyOqXoHUTBrnGspAA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yao Liu , Steve French , Sasha Levin , linux-cifs@vger.kernel.org Subject: [PATCH AUTOSEL 3.18 10/41] cifs: Fix NULL pointer dereference of devname Date: Wed, 27 Mar 2019 14:24:47 -0400 Message-Id: <20190327182518.19394-10-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327182518.19394-1-sashal@kernel.org> References: <20190327182518.19394-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yao Liu [ Upstream commit 68e2672f8fbd1e04982b8d2798dd318bf2515dd2 ] There is a NULL pointer dereference of devname in strspn() The oops looks something like: CIFS: Attempting to mount (null) BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 ... RIP: 0010:strspn+0x0/0x50 ... Call Trace: ? cifs_parse_mount_options+0x222/0x1710 [cifs] ? cifs_get_volume_info+0x2f/0x80 [cifs] cifs_setup_volume_info+0x20/0x190 [cifs] cifs_get_volume_info+0x50/0x80 [cifs] cifs_smb3_do_mount+0x59/0x630 [cifs] ? ida_alloc_range+0x34b/0x3d0 cifs_do_mount+0x11/0x20 [cifs] mount_fs+0x52/0x170 vfs_kern_mount+0x6b/0x170 do_mount+0x216/0xdc0 ksys_mount+0x83/0xd0 __x64_sys_mount+0x25/0x30 do_syscall_64+0x65/0x220 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fix this by adding a NULL check on devname in cifs_parse_devname() Signed-off-by: Yao Liu Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/cifs/connect.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 7d4c2bf2fea2..f5f5aab3457f 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1186,6 +1186,11 @@ cifs_parse_devname(const char *devname, struct smb_vol *vol) const char *delims = "/\\"; size_t len; + if (unlikely(!devname || !*devname)) { + cifs_dbg(VFS, "Device name not specified.\n"); + return -EINVAL; + } + /* make sure we have a valid UNC double delimiter prefix */ len = strspn(devname, delims); if (len != 2) -- 2.19.1