linux-kernel - [PATCH 5.2 327/413] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR

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Date:   Wed, 24 Jul 2019 21:20:18 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Nadav Amit <nadav.amit@...il.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 5.2 327/413] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value

From: Sean Christopherson <sean.j.christopherson@...el.com>

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@...r.kernel.org
Cc: Nadav Amit <nadav.amit@...il.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 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;