kernel security update

CentOS Errata and Security Advisory CESA-2013:1449

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

• A flaw was found in the way the Linux kernel handled the creation of
  temporary IPv6 addresses. If the IPv6 privacy extension was enabled
  (/proc/sys/net/ipv6/conf/eth0/use_tempaddr is set to ‘2’), an attacker on
  the local network could disable IPv6 temporary address generation, leading
  to a potential information disclosure. (CVE-2013-0343, Moderate)

• An information leak flaw was found in the way Linux kernel’s device
  mapper subsystem, under certain conditions, interpreted data written to
  snapshot block devices. An attacker could use this flaw to read data from
  disk blocks in free space, which are normally inaccessible. (CVE-2013-4299,
  Moderate)

• An off-by-one flaw was found in the way the ANSI CPRNG implementation in
  the Linux kernel processed non-block size aligned requests. This could lead
  to random numbers being generated with less bits of entropy than expected
  when ANSI CPRNG was used. (CVE-2013-4345, Moderate)

• An information leak flaw was found in the way Xen hypervisor emulated the
  OUTS instruction for 64-bit paravirtualized guests. A privileged guest user
  could use this flaw to leak hypervisor stack memory to the guest.
  (CVE-2013-4368, Moderate)

Red Hat would like to thank Fujitsu for reporting CVE-2013-4299, Stephan
Mueller for reporting CVE-2013-4345, and the Xen project for reporting
CVE-2013-4368.

This update also fixes the following bug:

• A bug in the GFS2 code prevented glock work queues from freeing
  glock-related memory while the glock memory shrinker repeatedly queued a
  large number of demote requests, for example when performing a simultaneous
  backup of several live GFS2 volumes with a large file count. As a
  consequence, the glock work queues became overloaded which resulted in a
  high CPU usage and the GFS2 file systems being unresponsive for a
  significant amount of time. A patch has been applied to alleviate this
  problem by calling the yield() function after scheduling a certain amount
  of tasks on the glock work queues. The problem can now occur only with
  extremely high work loads. (BZ#1014714)

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.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2013-October/082143.html

Affected packages:
kernel
kernel-PAE
kernel-PAE-devel
kernel-debug
kernel-debug-devel
kernel-devel
kernel-doc
kernel-headers
kernel-xen
kernel-xen-devel

Upstream details at:
https://access.redhat.com/errata/RHSA-2013:1449