kvm: nVMX: Don't allow L2 to access the hardware CR8
authorJim Mattson <jmattson@google.com>
Tue, 12 Sep 2017 20:02:54 +0000 (13:02 -0700)
committerPaolo Bonzini <pbonzini@redhat.com>
Fri, 15 Sep 2017 12:05:46 +0000 (14:05 +0200)
commit51aa68e7d57e3217192d88ce90fd5b8ef29ec94f
tree96b602951ac8eb47d92e93180f98cd470e2b7877
parent488e32f1981e506976d666b3772d6ccc8b726fee
kvm: nVMX: Don't allow L2 to access the hardware CR8

If L1 does not specify the "use TPR shadow" VM-execution control in
vmcs12, then L0 must specify the "CR8-load exiting" and "CR8-store
exiting" VM-execution controls in vmcs02. Failure to do so will give
the L2 VM unrestricted read/write access to the hardware CR8.

This fixes CVE-2017-12154.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/vmx.c