From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Sun, 21 Jul 2019 11:52:18 +0000 (+0200)
Subject: KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=79a431342a92c98f96a6a35ffda37b25ab0fecbe;p=linux

KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested

commit cf64527bb33f6cec2ed50f89182fc4688d0056b6 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index d36565dcc767..5ce6bd1eb43d 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -212,6 +212,8 @@ 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);