CVE request: kvm: check cpl before emulating debug register access

[Eugene Teo <eugene () redhat com>]

Quote from the upstream commit:
"Debug registers may only be accessed from cpl 0.  Unfortunately, vmx 
will code to emulate the instruction even though it was issued from 
guest userspace, possibly leading to an unexpected trap later."

Introduced in v2.6.30-rc1; Fixed in v2.6.32-rc1.

http://bugzilla.redhat.com/531660
http://git.kernel.org/linus/0a79b009525b160081d75cef5dbf45817956acf2

Thanks, Eugene
--
Eugene Teo / Red Hat Security Response Team