Path: news.gmane.org!not-for-mail From: Jeff Layton Newsgroups: gmane.linux.kernel.cifs Subject: [PATCH] cifs: fix possible memory corruption in CIFSFindNext Date: Tue, 23 Aug 2011 07:21:28 -0400 Lines: 37 Approved: news@gmane.org Message-ID: <1314098488-1547-1-git-send-email-jlayton@redhat.com> NNTP-Posting-Host: lo.gmane.org X-Trace: dough.gmane.org 1314098501 27164 80.91.229.12 (23 Aug 2011 11:21:41 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 23 Aug 2011 11:21:41 +0000 (UTC) Cc: linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dcl-HN4QTLPn1qTvY7RNz7mR4EEOCMrvLtNR@public.gmane.org To: smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Original-X-From: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Tue Aug 23 13:21:37 2011 Return-path: Envelope-to: glkc-linux-cifs-1dZseelyfdZg9hUCZPvPmw@public.gmane.org Original-Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Qvp33-0003JC-05 for glkc-linux-cifs-1dZseelyfdZg9hUCZPvPmw@public.gmane.org; Tue, 23 Aug 2011 13:21:37 +0200 Original-Received: (majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org) by vger.kernel.org via listexpand id S1752435Ab1HWLVg (ORCPT ); Tue, 23 Aug 2011 07:21:36 -0400 Original-Received: from mail-gy0-f174.google.com ([209.85.160.174]:43114 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751065Ab1HWLVf (ORCPT ); Tue, 23 Aug 2011 07:21:35 -0400 Original-Received: by gya6 with SMTP id 6so4228912gya.19 for ; Tue, 23 Aug 2011 04:21:35 -0700 (PDT) Original-Received: by 10.101.144.18 with SMTP id w18mr3505731ann.133.1314098494691; Tue, 23 Aug 2011 04:21:34 -0700 (PDT) Original-Received: from salusa.poochiereds.net (cpe-075-177-182-191.nc.res.rr.com [75.177.182.191]) by mx.google.com with ESMTPS id d33sm48355ano.35.2011.08.23.04.21.32 (version=SSLv3 cipher=OTHER); Tue, 23 Aug 2011 04:21:33 -0700 (PDT) X-Mailer: git-send-email 1.7.6 Original-Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Xref: news.gmane.org gmane.linux.kernel.cifs:4006 Archived-At: 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. Cc: Reported-by: Darren Lavender Signed-off-by: Jeff Layton --- fs/cifs/cifssmb.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index f4d0988..950464d 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -4089,7 +4089,8 @@ int CIFSFindNext(const int xid, struct cifs_tcon *tcon, 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"); -- 1.7.6