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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 ED755C282CE for ; Wed, 24 Apr 2019 17:16:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B362B2190A for ; Wed, 24 Apr 2019 17:16:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126202; bh=JYTsC0X+dz9DGNZNiAH/1wZX2PyBKd/GE1SlGGXBYUY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JNxIr3BzsQH2TfvymAf9hiSzTpIDzimKn3c4fnkHcOg4v4udCSY+oFE5j6gU73dY4 LhUXDusL54RCL835FOQ5dQJTR49NKLX7Vsqze18LWGNrcwGQtXzig2sE9IG1HvMKaK FVkBSeKAojPn+u00+SePl2ALqBvZ96zRw6x6zLIA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388473AbfDXRQl (ORCPT ); Wed, 24 Apr 2019 13:16:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:41254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388441AbfDXRQi (ORCPT ); Wed, 24 Apr 2019 13:16:38 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (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 39D6C21905; Wed, 24 Apr 2019 17:16:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126197; bh=JYTsC0X+dz9DGNZNiAH/1wZX2PyBKd/GE1SlGGXBYUY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=joojgkLVJpDB7INlogRirfd7Mezjn/rcesxFbhFYvU7uaeUjsXRLrFP/EH7njLLOY /qYcCVVuJNLansPR2lcAzs2rlWVHBCzxppT0NFxhE7/Go2/yZLAYF3oKhlrAo9MoNl 9u3GZCQJrrAC0IOfwfM+H2le6ffYpeopRNUCNjls= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yao Liu , Steve French , Sasha Levin Subject: [PATCH 4.4 025/168] cifs: Fix NULL pointer dereference of devname Date: Wed, 24 Apr 2019 19:07:49 +0200 Message-Id: <20190424170925.153843364@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170923.452349382@linuxfoundation.org> References: <20190424170923.452349382@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 [ 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 eacf57c24ca9..9cb72fd40eff 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1255,6 +1255,11 @@ 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