linux-kernel - [PATCH 15/43] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR

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Date:   Thu, 13 Jun 2019 19:03:01 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        vkuznets@...hat.com, stable@...r.kernel.org,
        Nadav Amit <nadav.amit@...il.com>
Subject: [PATCH 15/43] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value

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

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

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 1a87a91e98dc..091610684d28 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1894,9 +1894,10 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 					      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;
-- 
1.8.3.1