commit 5591bf07225523600450edd9e6ad258bb877b779
author Dan Rosenberg <drosenberg@vsecurity.com> Tue Sep 28 14:18:20 2010 -0400
committer Takashi Iwai <tiwai@suse.de> Tue Sep 28 21:33:16 2010 +0200
tree f886a48ec51861e74c79eca3052adeb9646d1534
parent e68d3b316ab7b02a074edc4f770e6a746390cb7d

ALSA: prevent heap corruption in snd_ctl_new()

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.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>