Issued:
2011-01-13
Updated:
2011-01-13

RHSA-2011:0028 - Low: kvm security and bug fix update

Synopsis

Low: kvm security and bug fix update

Type/Severity

Security Advisory Low

Topic

Updated kvm packages that fix one security issue and several bugs are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link 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 data structure field in kvm_vcpu_ioctl_x86_get_vcpu_events() in QEMU-KVM was not initialized properly before being copied to user-space. A privileged host user with access to "/dev/kvm" could use this flaw to leak kernel stack memory to user-space. (CVE-2010-4525)

Red Hat would like to thank Stephan Mueller of atsec information security for reporting this issue.

These updated packages also fix several bugs. Documentation for these bug fixes will be available shortly in the "kvm" section of the Red Hat Enterprise Linux 5.6 Technical Notes, linked to in the References.

All KVM users should upgrade to these updated packages, which resolve this issue as well as fixing the bugs noted in the Technical Notes. 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 This content is not included.http://kbase.redhat.com/faq/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

ProductVersionArch
Red Hat Enterprise Linux Workstation5x86_64
Red Hat Enterprise Linux Server5x86_64

Updated Packages

  • kvm-83-224.el5.x86_64.rpm
  • kvm-tools-83-224.el5.x86_64.rpm
  • kvm-83-224.el5.src.rpm
  • kvm-qemu-img-83-224.el5.x86_64.rpm
  • kmod-kvm-83-224.el5.x86_64.rpm
  • kmod-kvm-debug-83-224.el5.x86_64.rpm

Fixes

CVEs

References

Additional information