commit 4531662d1abf6c1f0e5c2b86ddb60e61509786c8
author Jim Mattson <jmattson@google.com> Tue May 23 11:52:54 2017 -0700
committer Radim Krčmář <rkrcmar@redhat.com> Wed Jun 07 16:28:55 2017 +0200
tree 9286a5be696514f307a64bf21328ab7a14d56725
parent 4439af9f911ae0243ffe4e2dfc12bace49605d8b

kvm: vmx: Check value written to IA32_BNDCFGS

Bits 11:2 must be zero and the linear addess in bits 63:12 must be
canonical. Otherwise, WRMSR(BNDCFGS) should raise #GP.

Fixes: 0dd376e709975779 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save")
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

arch/x86/kvm/vmx.c

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a339e97..3930129 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3279,6 +3279,9 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_IA32_BNDCFGS:
 		if (!kvm_mpx_supported() || !guest_cpuid_has_mpx(vcpu))
 			return 1;
+		if (is_noncanonical_address(data & PAGE_MASK) ||
+		    (data & MSR_IA32_BNDCFGS_RSVD))
+			return 1;
 		vmcs_write64(GUEST_BNDCFGS, data);
 		break;
 	case MSR_IA32_TSC: