DescriptionEugene Teo (Security Response)
2011-01-06 09:23:49 UTC
"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.
This only affects users who are using OSS (not to be confused with the OSS emulation provided by ALSA), and requires access to a device file normally restricted to users in group audio."
http://seclists.org/oss-sec/2010/q4/377
Upstream commit:
http://git.kernel.org/linus/d81a12bc29ae4038770e05dce4ab7f26fd5880fb
Acknowledgements:
Red Hat would like to thank Dan Rosenberg for reporting this issue.
Comment 2Eugene Teo (Security Response)
2011-01-11 09:33:35 UTC
Statement:
Not vulnerable. This issue did not affect the versions of Linux kernel as shipped with Red Hat Enterprise Linux 4, 5, 6 and Red Hat Enterprise MRG as they did not provide support for Open Sound System (OSS).