In theory, L1 can try to disable enlightened VMENTRY in VP assist page and
try to issue VMLAUNCH/VMRESUME. While nested_vmx_handle_enlightened_vmptrld()
properly handles this as 'EVMPTRLD_DISABLED', previously mapped eVMCS
remains mapped and thus all evmptr_is_valid() checks will still pass and
nested_vmx_run() will proceed when it shouldn't.
Release eVMCS immediately when we detect that enlightened vmentry was
disabled by L1.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index c662278e4793..ea2c52aad8f0 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1980,8 +1980,10 @@ static enum nested_evmptrld_status nested_vmx_handle_enlightened_vmptrld(
if (likely(!vmx->nested.enlightened_vmcs_enabled))
return EVMPTRLD_DISABLED;
- if (!nested_enlightened_vmentry(vcpu, &evmcs_gpa))
+ if (!nested_enlightened_vmentry(vcpu, &evmcs_gpa)) {
+ nested_release_evmcs(vcpu);
return EVMPTRLD_DISABLED;
+ }
if (unlikely(evmcs_gpa != vmx->nested.hv_evmcs_vmptr)) {
vmx->nested.current_vmptr = -1ull;
--
2.31.1
