kvm: vmx: Check value written to IA32_BNDCFGS
commit 4531662d1abf6c1f0e5c2b86ddb60e61509786c8 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index d8b5f8a..526d060 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -417,6 +417,8 @@
#define MSR_IA32_TSC_ADJUST 0x0000003b
#define MSR_IA32_BNDCFGS 0x00000d90
+#define MSR_IA32_BNDCFGS_RSVD 0x00000ffc
+
#define MSR_IA32_XSS 0x00000da0
#define FEATURE_CONTROL_LOCKED (1<<0)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index f57cb92..f5b9dae 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3284,6 +3284,9 @@ 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:
