An updated xorg-x11-drv-qxl package that fixes one security issue is now available for Red Hat Enterprise Linux 6.
The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) associated with each description below.
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.
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.