kmod, kvm security update

CentOS Errata and Security Advisory CESA-2012:1235

KVM (Kernel-based Virtual Machine) is a full virtualization solution for
Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built
for the standard Red Hat Enterprise Linux kernel.

A flaw was found in the way QEMU handled VT100 terminal escape sequences
when emulating certain character devices. A guest user with privileges to
write to a character device that is emulated on the host using a virtual
console back-end could use this flaw to crash the qemu-kvm process on the
host or, possibly, escalate their privileges on the host. (CVE-2012-3515)

This flaw did not affect the default use of KVM. Affected configurations
were:

• When guests were started from the command line (“/usr/libexec/qemu-kvm”),
  and without specifying a serial or parallel device that specifically does
  not use a virtual console (vc) back-end. (Note that Red Hat does not
  support invoking “qemu-kvm” from the command line on Red Hat Enterprise
  Linux 5.)

• Guests that were managed via libvirt, such as when using Virtual Machine
  Manager (virt-manager), but that have a serial or parallel device that uses
  a virtual console back-end. By default, guests managed via libvirt will not
  use a virtual console back-end for such devices.

Red Hat would like to thank the Xen project for reporting this issue.

All KVM users should upgrade to these updated packages, which correct this
issue. Note: The procedure in the Solution section must be performed before
this update will take effect.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2012-September/081009.html

Affected packages:
kmod-kvm
kmod-kvm-debug
kvm
kvm-qemu-img
kvm-tools

Upstream details at:
https://access.redhat.com/errata/RHSA-2012:1235