(RHSA-2014:0284) Important: kernel security and bug fix update

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

• A flaw was found in the way the Linux kernel’s IPv6 implementation
  handled certain UDP packets when the UDP Fragmentation Offload (UFO)
  feature was enabled. A remote attacker could use this flaw to crash the
  system or, potentially, escalate their privileges on the system.
  (CVE-2013-4387, Important)

• A flaw was found in the way the Linux kernel’s TCP/IP protocol suite
  implementation handled sending of certain UDP packets over sockets that
  used the UDP_CORK option when the UDP Fragmentation Offload (UFO) feature
  was enabled on the output device. A local, unprivileged user could use this
  flaw to cause a denial of service or, potentially, escalate their
  privileges on the system. (CVE-2013-4470, Important)

• A divide-by-zero flaw was found in the apic_get_tmcct() function in KVM’s
  Local Advanced Programmable Interrupt Controller (LAPIC) implementation.
  A privileged guest user could use this flaw to crash the host.
  (CVE-2013-6367, Important)

• A memory corruption flaw was discovered in the way KVM handled virtual
  APIC accesses that crossed a page boundary. A local, unprivileged user
  could use this flaw to crash the system or, potentially, escalate their
  privileges on the system. (CVE-2013-6368, Important)

• A buffer overflow flaw was found in the way the qeth_snmp_command()
  function in the Linux kernel’s QETH network device driver implementation
  handled SNMP IOCTL requests with an out-of-bounds length. A local,
  unprivileged user could use this flaw to crash the system or, potentially,
  escalate their privileges on the system. (CVE-2013-6381, Important)

• It was found that the fix for CVE-2012-2375 released via RHSA-2012:1580
  accidentally removed a check for small-sized result buffers. A local,
  unprivileged user with access to an NFSv4 mount with ACL support could use
  this flaw to crash the system or, potentially, escalate their privileges on
  the system. (CVE-2013-4591, Moderate)

• A format string flaw was found in the Linux kernel’s block layer.
  A privileged, local user could potentially use this flaw to escalate their
  privileges to kernel level (ring0). (CVE-2013-2851, Low)

Red Hat would like to thank Hannes Frederic Sowa for reporting
CVE-2013-4470, Andrew Honig of Google for reporting CVE-2013-6367 and
CVE-2013-6368, and Kees Cook for reporting CVE-2013-2851.

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.

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. The system must be
rebooted for this update to take effect.