The instruction decoder in arch/x86/kvm/emulate.c in the KVM subsystem in the Linux kernel before 3.18-rc2 lacks intended decoder-table flags for certain RIP-relative instructions, which allows guest OS users to cause a denial of service (NULL pointer dereference and host OS crash) via a crafted application.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=3f6f1480d86bf9fc16c160d803ab1d006e3058d5
thread.gmane.org/gmane.comp.emulators.kvm.devel/128427
www.openwall.com/lists/oss-security/2014/10/23/7
www.securityfocus.com/bid/70710
bugzilla.redhat.com/show_bug.cgi?id=1156615
github.com/torvalds/linux/commit/3f6f1480d86bf9fc16c160d803ab1d006e3058d5