According to the SDM, a VMWRITE in VMX non-root operation with an
invalid VMCS-link pointer results in VMfailInvalid before the validity
of the VMCS field in the secondary source operand is checked.
Fixes: 6d894f498f5d1 ("KVM: nVMX: vmread/vmwrite: Use shadow vmcs12 if running L2")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Cc: Liran Alon <liran.alon@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 4aea7d304beb..146e1b40c69f 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4864,6 +4864,25 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
if (vmx->nested.current_vmptr == -1ull)
return nested_vmx_failInvalid(vcpu);
+ if (!is_guest_mode(vcpu)) {
+ vmcs12 = get_vmcs12(vcpu);
+
+ /*
+ * Ensure vmcs12 is up-to-date before any VMWRITE that dirties
+ * vmcs12, else we may crush a field or consume a stale value.
+ */
+ if (!is_shadow_field_rw(field))
+ copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
+ } else {
+ /*
+ * When vmcs->vmcs_link_pointer is -1ull, any VMWRITE
+ * to shadowed-field sets the ALU flags for VMfailInvalid.
+ */
+ if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)
+ return nested_vmx_failInvalid(vcpu);
+ vmcs12 = get_shadow_vmcs12(vcpu);
+ }
+
if (vmx_instruction_info & (1u << 10))
field_value = kvm_register_readl(vcpu,
(((vmx_instruction_info) >> 3) & 0xf));
@@ -4889,25 +4908,6 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
return nested_vmx_failValid(vcpu,
VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT);
- if (!is_guest_mode(vcpu)) {
- vmcs12 = get_vmcs12(vcpu);
-
- /*
- * Ensure vmcs12 is up-to-date before any VMWRITE that dirties
- * vmcs12, else we may crush a field or consume a stale value.
- */
- if (!is_shadow_field_rw(field))
- copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
- } else {
- /*
- * When vmcs->vmcs_link_pointer is -1ull, any VMWRITE
- * to shadowed-field sets the ALU flags for VMfailInvalid.
- */
- if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)
- return nested_vmx_failInvalid(vcpu);
- vmcs12 = get_shadow_vmcs12(vcpu);
- }
-
offset = vmcs_field_to_offset(field);
if (offset < 0)
return nested_vmx_failValid(vcpu,
--
2.24.0.393.g34dc348eaf-goog
