KVM: x86 emulator: inject #UD on access to non-existing CR

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index fa4604e03250..836e97ba45da 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2520,6 +2520,13 @@ twobyte_insn:
                 c->dst.type = OP_NONE;
                 break;
         case 0x20: /* mov cr, reg */
+                switch (c->modrm_reg) {
+                case 1:
+                case 5 ... 7:
+                case 9 ... 15:
+                        kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
+                        goto done;
+                }
                 c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu);
                 c->dst.type = OP_NONE;  /* no writeback */
                 break;