From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932720Ab1I1Wom (ORCPT ); Wed, 28 Sep 2011 18:44:42 -0400 Received: from cantor2.suse.de ([195.135.220.15]:54334 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932695Ab1I1Woh (ORCPT ); Wed, 28 Sep 2011 18:44:37 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Sep 28 15:01:40 2011 Message-Id: <20110928220139.971823843@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 28 Sep 2011 15:01:43 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jeff Layton , Steve French Subject: [139/244] cifs: fix possible memory corruption in CIFSFindNext In-Reply-To: <20110928220225.GA27128@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jeff Layton commit 9438fabb73eb48055b58b89fc51e0bc4db22fabd upstream. The name_len variable in CIFSFindNext is a signed int that gets set to the resume_name_len in the cifs_search_info. The resume_name_len however is unsigned and for some infolevels is populated directly from a 32 bit value sent by the server. If the server sends a very large value for this, then that value could look negative when converted to a signed int. That would make that value pass the PATH_MAX check later in CIFSFindNext. The name_len would then be used as a length value for a memcpy. It would then be treated as unsigned again, and the memcpy scribbles over a ton of memory. Fix this by making the name_len an unsigned value in CIFSFindNext. Reported-by: Darren Lavender Signed-off-by: Jeff Layton Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/cifssmb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -4079,7 +4079,8 @@ int CIFSFindNext(const int xid, struct c T2_FNEXT_RSP_PARMS *parms; char *response_data; int rc = 0; - int bytes_returned, name_len; + int bytes_returned; + unsigned int name_len; __u16 params, byte_count; cFYI(1, "In FindNext");