[PRE-SA-2011-01] Multiple Linux kernel vulnerabilities in partition handling code of LDM and MAC partition tables

[Timo Warns <warns@xxxxxxxxxxxx>]

# PRE-CERT Security Advisory #

* Advisory: PRE-SA-2011-01
* Released on: 23 Feb 2011
* Last updated on: 23 Feb 2011
* Affected product: Linux Kernel 2.4 and 2.6
* Impact: - privilege Escalation
          - denial-of-service
          - disclosure of sensitive information
* Origin: storage devices
* CVE Identifier: - CVE-2011-1010

## Summary ##

Timo Warns (PRESENSE Technologies GmbH) reported some vulnerabilities in
the Linux kernel that may lead to privilege escalation,
denial-of-service, or information leakage via corrupted partition
tables. Exploiting these vulnerabilities has been demonstrated by a "USB
Stick of Death" that crashes the Linux kernel upon connecting the stick.

The kernel automatically evaluates partition tables of storage devices.
Note that this happens independently of whether auto-mounting is enabled
or not. The code for evaluating MAC and LDM partition tables contains the
following vulnerabilities:

* CVE-2011-1010
  A buffer overflow bug in mac_partition in fs/partitions/mac.c (for MAC
  partition tables) allows to cause a denial-of-service (kernel panic)
  via a corrupted MAC partition table.

  For a patch, see
  http://git.kernel.org/linus/fa7ea87a057958a8b7926c1a60a3ca6d696328ed

* A division-by-zero bug in ldm_get_vblks in fs/partitions/ldm.c (for
  LDM partition tables) allows to cause a denial-of-service (kernel
  oops) via a corrupted LDM partition table.

  For a patch, see
  http://www.spinics.net/lists/mm-commits/msg82429.html

* A buffer overflow bug in ldm_frag_add in fs/partitions/ldm.c (for LDM
  partition tables) may allow to escalate privileges or to disclose
  sensitive information via a corrupted LDM partition table.

## Workaround ##

Compile and use a kernel that does not evaluate MAC and LDM partition
tables. The corresponding configuration keys are CONFIG_MAC_PARTITION
and CONFIG_LDM_PARTITION.

## References ##

https://bugzilla.redhat.com/show_bug.cgi?id=679282

When further information becomes available, this advisory will be
updated. The most recent version of this advisory is available at:

http://www.pre-cert.de/advisories/PRE-SA-2011-01.txt

## Contact ##

PRE-CERT can be reached under precert@xxxxxxxxxxxxxx For PGP
key information, refer to http://www.pre-cert.de