(RHSA-2011:1801) Important: qemu-kvm security update

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

A flaw was found in the way qemu-kvm handled VSC_ATR messages when a guest
was configured for a CCID (Chip/Smart Card Interface Devices) USB smart
card reader in passthrough mode. An attacker able to connect to the port on
the host being used for such a device could use this flaw to crash the
qemu-kvm process on the host or, possibly, escalate their privileges on the
host. (CVE-2011-4111)

All users of qemu-kvm should upgrade to these updated packages, which
contain a backported patch to resolve 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.