Re: CVE request - kernel: prevent heap corruption in snd_ctl_new()

[Eugene Teo <eugene () redhat com>]

On 09/29/2010 03:01 PM, Marcus Meissner wrote:
> 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.

Please use this link.

http://git.kernel.org/?p=linux/kernel/git/tiwai/sound-2.6.git;a=commitdiff;h=5591bf07225523600450edd9e6ad258bb877b779

Eugene
--
main(i) { putchar(182623909 >> (i-1) * 5&31|!!(i<7)<<6) && main(++i); }