Issued:
2015-05-13
Updated:
2015-05-13

RHSA-2015:1003 - Important: kvm security update

Synopsis

Important: kvm security update

Type/Severity

Security Advisory Important

Topic

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

Red Hat Product Security has rated this update as having Important 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.

An out-of-bounds memory access flaw was found in the way QEMU's virtual Floppy Disk Controller (FDC) handled FIFO buffer access while processing certain FDC commands. A privileged guest user could use this flaw to crash the guest or, potentially, execute arbitrary code on the host with the privileges of the host's QEMU process corresponding to the guest. (CVE-2015-3456)

Red Hat would like to thank Jason Geffner of CrowdStrike for reporting this issue.

All kvm users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. 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.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

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-83-272.el5_11.x86_64.rpm
  • kmod-kvm-debug-83-272.el5_11.x86_64.rpm
  • kvm-83-272.el5_11.src.rpm
  • kmod-kvm-83-272.el5_11.x86_64.rpm
  • kvm-qemu-img-83-272.el5_11.x86_64.rpm
  • kvm-tools-83-272.el5_11.x86_64.rpm
  • kvm-debuginfo-83-272.el5_11.x86_64.rpm

Fixes

CVEs

References

Additional information