[PATCH 1/2] KVM: VMX: Add non-canonical check on writes to RTIT address MSRs

From: Sean Christopherson
Date: Tue Dec 10 2019 - 18:24:47 EST


Reject writes to RTIT address MSRs if the data being written is a
non-canonical address as the MSRs are subject to canonical checks, e.g.
KVM will trigger an unchecked #GP when loading the values to hardware
during pt_guest_enter().

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 51e3b27f90ed..9aa2006dbe04 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2152,6 +2152,8 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
(index >= 2 * intel_pt_validate_cap(vmx->pt_desc.caps,
PT_CAP_num_address_ranges)))
return 1;
+ if (is_noncanonical_address(data, vcpu))
+ return 1;
if (index % 2)
vmx->pt_desc.guest.addr_b[index / 2] = data;
else
--
2.24.0