[PATCH 5.2 327/413] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value

From: Greg Kroah-Hartman
Date: Wed Jul 24 2019 - 15:38:47 EST


From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

commit d28f4290b53a157191ed9991ad05dffe9e8c0c89 upstream.

The behavior of WRMSR is in no way dependent on whether or not KVM
consumes the value.

Fixes: 4566654bb9be9 ("KVM: vmx: Inject #GP on invalid PAT CR")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kvm/vmx/vmx.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1896,9 +1896,10 @@ static int vmx_set_msr(struct kvm_vcpu *
MSR_TYPE_W);
break;
case MSR_IA32_CR_PAT:
+ if (!kvm_pat_valid(data))
+ return 1;
+
if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
- if (!kvm_pat_valid(data))
- return 1;
vmcs_write64(GUEST_IA32_PAT, data);
vcpu->arch.pat = data;
break;