RHSA-2016:0083 — Security Advisory

Updated qemu-kvm packages that fix one security issue and one bug are now available for Red Hat Enterprise Linux 7.

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.

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.

An out-of-bounds read/write flaw was discovered in the way QEMU's Firmware Configuration device emulation processed certain firmware configurations. A privileged (CAP_SYS_RAWIO) guest user could use this flaw to crash the QEMU process instance or, potentially, execute arbitrary code on the host with privileges of the QEMU process. (CVE-2016-1714)

Red Hat would like to thank Donghai Zhu of Alibaba for reporting this issue.

This update also fixes the following bugs:

• Incorrect handling of the last sector of an image file could trigger an assertion failure in qemu-img. This update changes the handling of the last sector, and no assertion failure occurs. (BZ#1298828)

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.