(RHSA-2015:1031) Important: qemu-kvm security update

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