Issued:
2012-02-21
Updated:
2012-02-21

RHSA-2012:0149 - Moderate: kvm security and bug fix update

Synopsis

Moderate: kvm security and bug fix update

Type/Severity

Security Advisory Moderate

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 moderate 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.

It was found that the kvm_vm_ioctl_assign_device() function in the KVM subsystem of a Linux kernel did not check if the user requesting device assignment was privileged or not. A member of the kvm group on the host could assign unused PCI devices, or even devices that were in use and whose resources were not properly claimed by the respective drivers, which could result in the host crashing. (CVE-2011-4347)

Red Hat would like to thank Sasha Levin for reporting this issue.

These updated kvm packages include several bug fixes. Space precludes documenting all of these changes in this advisory. Users are directed to the Red Hat Enterprise Linux 5.8 Technical Notes, linked to in the References, for information on the most significant of these changes.

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 This content is not included.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

ProductVersionArch
Red Hat Enterprise Linux Workstation5x86_64
Red Hat Enterprise Linux Server5x86_64

Updated Packages

  • kmod-kvm-83-249.el5.x86_64.rpm
  • kvm-debuginfo-83-249.el5.x86_64.rpm
  • kvm-tools-83-249.el5.x86_64.rpm
  • kvm-83-249.el5.src.rpm
  • kvm-qemu-img-83-249.el5.x86_64.rpm
  • kmod-kvm-debug-83-249.el5.x86_64.rpm
  • kvm-83-249.el5.x86_64.rpm

Fixes

CVEs

References

Additional information