Synopsis

Important: kvm security update

Type/Severity

Security Advisory: Important

Topic

Updated kvm packages that fix two security issues are now available for
Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having
important security impact. Common Vulnerability Scoring System (CVSS) base
scores, which give detailed severity ratings, are available for each
vulnerability from the CVE links in the References section.

Description

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 heap overflow flaw was found in the way QEMU-KVM emulated the e1000
network interface card. A privileged guest user in a virtual machine whose
network interface is configured to use the e1000 emulated driver could use
this flaw to crash the host or, possibly, escalate their privileges on the
host. (CVE-2012-0029)

A flaw was found in the way the KVM subsystem of a Linux kernel handled PIT
(Programmable Interval Timer) IRQs (interrupt requests) when there was no
virtual interrupt controller set up. A malicious user in the kvm group on
the host could force this situation to occur, resulting in the host
crashing. (CVE-2011-4622)

Red Hat would like to thank Nicolae Mogoreanu for reporting CVE-2012-0029.

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

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

The following procedure must be performed before this update will take
effect:

1) Stop all KVM guest virtual machines.

2) Either reboot the hypervisor machine or, as the root user, remove (using
"modprobe -r [module]") and reload (using "modprobe [module]") all of the
following modules which are currently running (determined using "lsmod"):
kvm, ksm, kvm-intel or kvm-amd.

3) Restart the KVM guest virtual machines.

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Workstation 5 x86_64

Fixes

• BZ - 769721 - CVE-2011-4622 kernel: kvm: pit timer with no irqchip crashes the system
• BZ - 772075 - CVE-2012-0029 qemu-kvm: e1000: process_tx_desc legacy mode packets heap overflow

CVEs

• CVE-2012-0029
• CVE-2011-4622

References

• https://access.redhat.com/security/updates/classification/#important

Red Hat Enterprise Linux Server 5

SRPM
x86_64
kmod-kvm-83-239.el5_7.1.x86_64.rpm	SHA-256: cc897806f3bd7ba12bdcb394fa1e0a0e1cb02da062dcc4dbdb5113c28d1ea30e
kmod-kvm-debug-83-239.el5_7.1.x86_64.rpm	SHA-256: e90a73593da313cf806014cb847fb81530f63c5c20133f26aee9ef25ee661e6a
kvm-83-239.el5_7.1.x86_64.rpm	SHA-256: 0a14d19889445c53004d7654788f37da4bdf3080dd1356ba1f8c88194da74c0b
kvm-qemu-img-83-239.el5_7.1.x86_64.rpm	SHA-256: 59ab5834f34b1a691bb2244aba4eaf519051b323596217da0f76d3772ab4f6b8
kvm-tools-83-239.el5_7.1.x86_64.rpm	SHA-256: ca5ca8d3d4ae2c2c2eb354dad4755f03db61deaaeea31804680779c4c3a5ba04

Red Hat Enterprise Linux Workstation 5

SRPM
x86_64
kmod-kvm-83-239.el5_7.1.x86_64.rpm	SHA-256: cc897806f3bd7ba12bdcb394fa1e0a0e1cb02da062dcc4dbdb5113c28d1ea30e
kmod-kvm-debug-83-239.el5_7.1.x86_64.rpm	SHA-256: e90a73593da313cf806014cb847fb81530f63c5c20133f26aee9ef25ee661e6a
kvm-83-239.el5_7.1.x86_64.rpm	SHA-256: 0a14d19889445c53004d7654788f37da4bdf3080dd1356ba1f8c88194da74c0b
kvm-qemu-img-83-239.el5_7.1.x86_64.rpm	SHA-256: 59ab5834f34b1a691bb2244aba4eaf519051b323596217da0f76d3772ab4f6b8
kvm-tools-83-239.el5_7.1.x86_64.rpm	SHA-256: ca5ca8d3d4ae2c2c2eb354dad4755f03db61deaaeea31804680779c4c3a5ba04