xen security update

CentOS Errata and Security Advisory CESA-2015:1002

The xen packages contain administration tools and the xend service for
managing the kernel-xen kernel for virtualization on Red Hat Enterprise
Linux.

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 xen users are advised to upgrade to these updated packages, which
contain a backported patch to correct this issue. After installing the
updated packages, all running fully-virtualized guests must be restarted
for this update to take effect.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2015-May/083297.html

Affected packages:
xen
xen-devel
xen-libs

Upstream details at:
https://access.redhat.com/errata/RHSA-2015:1002