KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested

Letting this pend may cause nested_get_vmcs12_pages to run against an
invalid state, corrupting the effective vmcs of L1.

This was triggerable in QEMU after a guest corruption in L2, followed by
a L1 reset.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 7f7f1ba33cf2 ("KVM: x86: do not load vmcs12 pages while still in SMM")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 0f13787..4cdab4b 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -220,6 +220,8 @@ static void free_nested(struct kvm_vcpu *vcpu)
        if (!vmx->nested.vmxon && !vmx->nested.smm.vmxon)
                return;
 
+       kvm_clear_request(KVM_REQ_GET_VMCS12_PAGES, vcpu);
+
        vmx->nested.vmxon = false;
        vmx->nested.smm.vmxon = false;
        free_vpid(vmx->nested.vpid02);