Re: [Full-disclosure] Linux Kernel CIFS Vulnerability

[Marcus Meissner <meissner@xxxxxxx>]

On Thu, Apr 09, 2009 at 03:07:40PM +0200, Andreas Bogk wrote:
> Dear list,
> 
> as discovered by Felix von Leitner (http://blog.fefe.de/?ts=b72905a8), 
> Linux kernel patch 2.6.29.1 contains:
> 
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -3667,7 +3667,7 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses,
>                             BCC(smb_buffer_response)) {
>                                 kfree(tcon->nativeFileSystem);
>                                 tcon->nativeFileSystem =
> -                                   kzalloc(length + 2, GFP_KERNEL);
> +                                   kzalloc(2*(length + 1), GFP_KERNEL);
>                                 if (tcon->nativeFileSystem)
>                                         cifs_strfromUCS_le(
>                                                 tcon->nativeFileSystem,
> 
> fixing a remotely exploitable buffer overflow vulnerability in the CIFS 
> protocol.

assuming a malicious server.

> Neither the Linux kernel team, the CIFS maintainers nor any of the commercial 
> Linux distributors bothered to send out an advisory.
> I'm at loss for words other than "irresponsible, arrogant assholes".  Linux 
> 2009 == Microsoft 2002.

The correct wording is "no advisory was released yet".

The issue is being worked on already, see the CIFS mailing list etc, thread
starts here:
http://lists.samba.org/archive/linux-cifs-client/2009-April/004322.html

Updates will be published when ready.

Ciao, Marcus

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