RHSA-2014:1075 - Security Advisory

Topic

Updated qemu-kvm packages that fix two security issues and three bugs are
now available for Red Hat Enterprise Linux 6.

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 package provides the
user-space component for running virtual machines using KVM.

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 bugs:

• 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#1109715)

• This update enables ioeventfd in virtio-scsi-pci. This allows QEMU to

process I/O requests outside of the vCPU thread, reducing the latency of
submitting requests and improving single task throughput. (BZ#1123271)

• Prior to this update, vendor-specific SCSI commands issued from a KVM

guest did not reach the target device due to QEMU considering such commands
as invalid. This update fixes this bug by properly propagating
vendor-specific SCSI commands to the target device. (BZ#1125131)

All qemu-kvm users 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 Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 i386
• Red Hat Enterprise Linux Server - AUS 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Server - TUS 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 i386
• Red Hat Enterprise Linux EUS Compute Node 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386

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 - 1109715 - live incremental migration of vm with common shared base, size(disk) > size(base) transfers unallocated sectors, explodes disk on dest
• BZ - 1123271 - Enable ioenventfd for virtio-scsi-pci

CVEs

• CVE-2014-0223
• CVE-2014-0222

References

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