Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 7 Apr 2009 13:59:25 -0500
From: Steven French <sfrench@...ibm.com>
To: Eugene Teo <eugene@...hat.com>
Cc: Marcus Meissner <meissner@...e.de>, oss-security@...ts.openwall.com,
        security@...nel.org
Subject: Re: CVE request? buffer overflow in CIFS in 2.6.*

Yes - the NativeFileSystem field is part of a server generated response 
and is typically tiny ("NTFS" for example).

As soon as Suresh (or his coworkers at  Novell) have a patch - we (Jeff 
and I etc.) will review it.  I think fixing these conversions to be 
cleaner is important, although the risk of exploitable overflow is small 
in practice.


Steve French
Senior Software Engineer
Linux Technology Center - IBM Austin
phone: 512-838-2294
email: sfrench at-sign us dot ibm dot com



Eugene Teo <eugene@...hat.com> 
04/07/2009 12:41 AM

To
Marcus Meissner <meissner@...e.de>
cc
oss-security@...ts.openwall.com, security@...nel.org, Steven 
French/Austin/IBM@...US
Subject
Re: [oss-security] CVE request? buffer overflow in CIFS in 2.6.*






Hi Marcus,

Marcus Meissner wrote:
> Fixes a kmalloc area overflow in CIFS, number of overwritten bytes
> is depending on the codepage converted to.
> 
> The data seems to come from a remote generated reply blob even, correct
> me if I am wrong. :/

Looks like it's part of the session setup. The NativeFileSystem field is
part of the Tree Connect response (TCon for short).

> And I wonder if "len*2" is sufficient, can't a UCS -> UTF8 conversion
> generate more than 2 byte utf-8 characters for 1 ucs character?

I understand that someone from your side is working on a better patch
for this. Do keep us updated when it goes upstream.

Thanks, Eugene
-- 
Eugene Teo / Red Hat Security Response Team


Powered by blists - more mailing lists

Your e-mail address:

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.