linux-2.6 - several

Several vulnerabilities have been discovered in the Linux kernel that may lead
to a denial of service or privilege escalation. The Common Vulnerabilities and
Exposures project identifies the following problems:

• CVE-2011-4086
  Eric Sandeen reported an issue in the journaling layer for ext4 filesystems
  (jbd2). Local users can cause buffers to be accessed after they have been
  torn down, resulting in a denial of service (DoS) due to a system crash.
• CVE-2012-0879
  Louis Rilling reported two reference counting issues in the CLONE_IO
  feature of the kernel. Local users can prevent io context structures
  from being freed, resulting in a denial of service.
• CVE-2012-1601
  Michael Ellerman reported an issue in the KVM subsystem. Local users could
  cause a denial of service (NULL pointer dereference) by creating VCPUs
  before a call to KVM_CREATE_IRQCHIP.
• CVE-2012-2123
  Steve Grubb reported an issue in fcaps, a filesystem-based capabilities
  system. Personality flags set using this mechanism, such as the disabling
  of address space randomization, may persist across suid calls.
• CVE-2012-2133
  Shachar Raindel discovered a use-after-free bug in the hugepages
  quota implementation. Local users with permission to use hugepages
  via the hugetlbfs implementation may be able to cause a denial of
  service (system crash).

For the stable distribution (squeeze), this problem has been fixed in version
2.6.32-44. Updates are currently only available for the amd64, i386 and sparc
ports.

Note: updated linux-2.6 packages will also be made available in the release
of Debian 6.0.5, scheduled to take place the weekend of 2012.05.12. This
pending update will be version 2.6.32-45, and provides an additional fix for
build failures on some architectures. Users for whom this update is not
critical, and who may wish to avoid multiple reboots, should consider waiting
for the 6.0.5 release before updating, or installing the 2.6.32-45 version
ahead of time from proposed-updates.

The following matrix lists additional source packages that were rebuilt for
compatibility with or to take advantage of this update:

We recommend that you upgrade your linux-2.6 and user-mode-linux packages.