tree 69b5439b49368704465f797ff7ae147e3d81d451
parent 7693457547b729d9010a6014bbb8572b085f58d4
author Dan Rosenberg <drosenberg@vsecurity.com> 1293312220 -0500
committer Takashi Iwai <tiwai@suse.de> 1293711655 +0100

sound: Prevent buffer overflow in OSS load_mixer_volumes

The load_mixer_volumes() function, which can be triggered by
unprivileged users via the SOUND_MIXER_SETLEVELS ioctl, is vulnerable to
a buffer overflow.  Because the provided "name" argument isn't
guaranteed to be NULL terminated at the expected 32 bytes, it's possible
to overflow past the end of the last element in the mixer_vols array.
Further exploitation can result in an arbitrary kernel write (via
subsequent calls to load_mixer_volumes()) leading to privilege
escalation, or arbitrary kernel reads via get_mixer_levels().  In
addition, the strcmp() may leak bytes beyond the mixer_vols array.

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