(RHSA-2013:0218) Moderate: xorg-x11-drv-qxl security update

The xorg-x11-drv-qxl package provides an X11 video driver for the QEMU QXL
video accelerator. This driver makes it possible to use Red Hat Enterprise
Linux 6 as a guest operating system under the KVM kernel module and the
QEMU multi-platform emulator, using the SPICE protocol.

A flaw was found in the way the host’s qemu-kvm qxl driver and the guest’s
X.Org qxl driver interacted when a SPICE connection terminated. A user able
to initiate a SPICE connection to a guest could use this flaw to make the
guest temporarily unavailable or, potentially (if the sysctl
kernel.softlockup_panic variable was set to “1” in the guest), crash the
guest. (CVE-2013-0241)

All users of xorg-x11-drv-qxl are advised to upgrade to this updated
package, which contains a backported patch to correct this issue. All
running X.Org server instances using the qxl driver must be restarted for
this update to take effect.