(RHSA-2013:0223) Moderate: kernel security and bug fix update

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

This update fixes the following security issues:

• It was found that a deadlock could occur in the Out of Memory (OOM)
  killer. A process could trigger this deadlock by consuming a large amount
  of memory, and then causing request_module() to be called. A local,
  unprivileged user could use this flaw to cause a denial of service
  (excessive memory consumption). (CVE-2012-4398, Moderate)

• A flaw was found in the way the KVM (Kernel-based Virtual Machine)
  subsystem handled guests attempting to run with the X86_CR4_OSXSAVE CPU
  feature flag set. On hosts without the XSAVE CPU feature, a local,
  unprivileged user could use this flaw to crash the host system. (The
  “grep --color xsave /proc/cpuinfo” command can be used to verify if your
  system has the XSAVE CPU feature.) (CVE-2012-4461, Moderate)

• A memory disclosure flaw was found in the way the load_script() function
  in the binfmt_script binary format handler handled excessive recursions. A
  local, unprivileged user could use this flaw to leak kernel stack memory to
  user-space by executing specially-crafted scripts. (CVE-2012-4530, Low)

Red Hat would like to thank Tetsuo Handa for reporting CVE-2012-4398, and
Jon Howell for reporting CVE-2012-4461.

This update also fixes several bugs. Documentation for these changes will
be available shortly from the Technical Notes document linked to in the
References section.

Users should upgrade to these updated packages, which contain backported
patches to correct these issues, and fix the bugs noted in the Technical
Notes. The system must be rebooted for this update to take effect.