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=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 BADDBC43381 for ; Wed, 27 Mar 2019 18:44:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82EC1205C9 for ; Wed, 27 Mar 2019 18:44:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553712275; bh=Do+97uAGXIRSfV9q24bcN96ipIpTYk9+VIffGp3ehxk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=n7UrRGmSg+DehRf5Ky3Za608SF61Ecrwl7VSlD8xaQfzSMoRygpTVprHwSwYs3aZS SZOf99oPfLckjY3/GS/GBgv1xty1LqilFL1f8YXRb5tVK4wUm3okC7UDt9gRc1rl9+ Ls86hjXnGLdK7qlP5h9j0WsPlngEwT8ZPjF1AZS4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391102AbfC0SVQ (ORCPT ); Wed, 27 Mar 2019 14:21:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:39066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391098AbfC0SVP (ORCPT ); Wed, 27 Mar 2019 14:21:15 -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 BDC6D217D9; Wed, 27 Mar 2019 18:21:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553710874; bh=Do+97uAGXIRSfV9q24bcN96ipIpTYk9+VIffGp3ehxk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cmJ9jCJMc7q1ZZzLjKwRTkTVtBzNZiNQip6LVQ4kloyI6dr8ca83CgYjPknI8Lh0I 2PmOyv/Jostccair8wqmo5orB/dskV0wLKblM3620cu/Evo3yKTaIx+t7G0xFlBATD oDsFCqLk8Rju8SrD1z7vf2BL3NW6Ud30LrwQtJL8= 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 4.9 19/87] cifs: Fix NULL pointer dereference of devname Date: Wed, 27 Mar 2019 14:19:32 -0400 Message-Id: <20190327182040.17444-19-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327182040.17444-1-sashal@kernel.org> References: <20190327182040.17444-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 33e65b71c49a..f291ed0c155d 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1201,6 +1201,11 @@ 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