KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for the standard Red Hat Enterprise Linux kernel.
It was found that KVM's Write to Model Specific Register (WRMSR) instruction emulation would write non-canonical values passed in by the guest to certain MSRs in the host's context. A privileged guest user could use this flaw to crash the host. (CVE-2014-3610)
A race condition flaw was found in the way the Linux kernel's KVM subsystem handled PIT (Programmable Interval Timer) emulation. A guest user who has access to the PIT I/O ports could use this flaw to crash the host. (CVE-2014-3611)
Red Hat would like to thank Lars Bull of Google and Nadav Amit for reporting the CVE-2014-3610 issue, and Lars Bull of Google for reporting the CVE-2014-3611 issue.
All kvm users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. Note: The procedure in the Solution section must be performed before this update will take effect.