linux-kernel - [PATCH AUTOSEL 4.19 133/167] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR

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Message-Id: <20190903162519.7136-133-sashal@kernel.org>
Date:   Tue,  3 Sep 2019 12:24:45 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Nadav Amit <nadav.amit@...il.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sasha Levin <sashal@...nel.org>, kvm@...r.kernel.org
Subject: [PATCH AUTOSEL 4.19 133/167] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value

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

[ Upstream commit d28f4290b53a157191ed9991ad05dffe9e8c0c89 ]

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: Sasha Levin <sashal@...nel.org>
---
 arch/x86/kvm/vmx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index feff7ed44a2bb..e4bba840a0708 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4265,9 +4265,10 @@ 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;
-- 
2.20.1