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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2014-8480
• torvalds/linux@3f6f148
• https://bugzilla.redhat.com/show_bug.cgi?id=1156615
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3f6f1480d86bf9fc16c160d803ab1d006e3058d5
• http://thread.gmane.org/gmane.comp.emulators.kvm.devel/128427
• http://www.openwall.com/lists/oss-security/2014/10/23/7
• http://www.securityfocus.com/bid/70710