RHSA-2014:1076 - Security Advisory

Topic

Updated qemu-kvm-rhev packages that fix two security issues and one bug are
now available for Red Hat Enterprise Virtualization.

Red Hat Product Security has rated this update as having Moderate 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. The qemu-kvm-rhev package provides the
user-space component for running virtual machines using KVM in environments
managed by Red Hat Enterprise Virtualization Manager.

Two integer overflow flaws were found in the QEMU block driver for QCOW
version 1 disk images. A user able to alter the QEMU disk image files
loaded by a guest could use either of these flaws to corrupt QEMU process
memory on the host, which could potentially result in arbitrary code
execution on the host with the privileges of the QEMU process.
(CVE-2014-0222, CVE-2014-0223)

Red Hat would like to thank NSA for reporting these issues.

This update also fixes the following bug:

• In certain scenarios, when performing live incremental migration, the

disk size could be expanded considerably due to the transfer of unallocated
sectors past the end of the base image. With this update, the
bdrv_is_allocated() function has been fixed to no longer return "True" for
unallocated sectors, and the disk size no longer changes after performing
live incremental migration. (BZ#1110681)

All users of qemu-kvm-rhev are advised to upgrade to these updated
packages, which contain backported patches to correct these issues. After
installing this update, shut down all running virtual machines. Once all
virtual machines have shut down, start them again for this update to 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/articles/11258

Affected Products

• Red Hat Virtualization 3 for RHEL 6 x86_64

Fixes

• BZ - 1097216 - CVE-2014-0222 Qemu: qcow1: validate L2 table size to avoid integer overflows
• BZ - 1097222 - CVE-2014-0223 Qemu: qcow1: validate image size to avoid out-of-bounds memory access
• BZ - 1110681 - live incremental migration of vm with common shared base, size(disk) > size(base) transfers unallocated sectors, explodes disk on dest - qemu-kvm-rhev clone

CVEs

• CVE-2014-0223
• CVE-2014-0222

References

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