oss-security - Re: CVE request - kernel: prevent heap corruption in snd_ctl

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Date: Wed, 29 Sep 2010 09:01:15 +0200
From: Marcus Meissner <meissner@...e.de>
To: oss-security@...ts.openwall.com
Cc: "Steven M. Christey" <coley@...us.mitre.org>
Subject: Re: CVE request - kernel: prevent heap corruption in snd_ctl_new()

On Wed, Sep 29, 2010 at 02:49:52PM +0800, Eugene Teo wrote:
> Reported by Dan Rosenberg. The snd_ctl_new() function in 
> sound/core/control.c allocates space for a snd_kcontrol struct by 
> performing arithmetic operations on a user-provided size without 
> checking for integer overflow.  If a user provides a large enough size, 
> an overflow will occur, the allocated chunk will be too small, and a 
> second user-influenced value will be written repeatedly past the bounds 
> of this chunk. This code is reachable by unprivileged users who have 
> permission to open a /dev/snd/controlC* device (on many distros, this is 
> group "audio") via the SNDRV_CTL_IOCTL_ELEM_ADD and 
> SNDRV_CTL_IOCTL_ELEM_REPLACE ioctls.
> 
> Upstream commit:
> http://git.kernel.org/linus/5591bf07225523600450edd9e6ad258bb877b779

Doesnt seem to be valid. There is also no change in sounds/core/control.c
since April in current mainline git.
 
Ciao, Marcus

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