The recalculate_apic_map function in arch/x86/kvm/lapic.c in the KVM subsystem in the Linux kernel through 3.12.5 allows guest OS users to cause a denial of service (host OS crash) via a crafted ICR write operation in x2apic mode.
http://lists.opensuse.org/opensuse-security-announce/2014-02/msg00002.html
http://lists.opensuse.org/opensuse-security-announce/2014-02/msg00003.html
https://bugzilla.redhat.com/show_bug.cgi?id=1033106
https://github.com/torvalds/linux/commit/17d68b763f09a9ce824ae23eb62c9efc57b69271
http://www.openwall.com/lists/oss-security/2013/12/12/12
http://www.ubuntu.com/usn/USN-2113-1