[PATCH 5.10 18/93] KVM: x86: nSVM: dont copy virt_ext from vmcb12

Greg Kroah-Hartman
2021-10-04T13:24:15Z

From: Maxim Levitsky <mlevitsk@redhat.com>

commit faf6b755629627f19feafa75b32e81cd7738f12d upstream.

These field correspond to features that we don't expose yet to L2

While currently there are no CVE worthy features in this field,
if AMD adds more features to this field, that could allow guest
escapes similar to CVE-2021-3653 and CVE-2021-3656.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210914154825.104886-6-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/svm/nested.c | 1 -
1 file changed, 1 deletion(-)

--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -447,7 +447,6 @@ static void nested_prepare_vmcb_control(
(svm->nested.ctl.int_ctl & int_ctl_vmcb12_bits) |
(svm->nested.hsave->control.int_ctl & int_ctl_vmcb01_bits);

- svm->vmcb->control.virt_ext = svm->nested.ctl.virt_ext;
svm->vmcb->control.int_vector = svm->nested.ctl.int_vector;
svm->vmcb->control.int_state = svm->nested.ctl.int_state;
svm->vmcb->control.event_inj = svm->nested.ctl.event_inj;