(RHSA-2017:0083) Low: qemu-kvm security and bug fix update

Kernel-based Virtual Machine (KVM) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. The qemu-kvm packages provide the user-space component for running virtual machines using KVM.

Security Fix(es):

• An out-of-bounds read-access flaw was found in the QEMU emulator built with IP checksum routines. The flaw could occur when computing a TCP/UDP packet’s checksum, because a QEMU function used the packet’s payload length without checking against the data buffer’s size. A user inside a guest could use this flaw to crash the QEMU process (denial of service). (CVE-2016-2857)

Red Hat would like to thank Ling Liu (Qihoo 360 Inc.) for reporting this issue.

Bug Fix(es):

• Previously, rebooting a guest virtual machine more than 128 times in a short period of time caused the guest to shut down instead of rebooting, because the virtqueue was not cleaned properly. This update ensures that the virtqueue is cleaned more reliably, which prevents the described problem from occurring. (BZ#1393484)