Maxim Levitsky c7dfa40099 KVM: nSVM: always intercept VMLOAD/VMSAVE when nested (CVE-2021-3656)
If L1 disables VMLOAD/VMSAVE intercepts, and doesn't enable
Virtual VMLOAD/VMSAVE (currently not supported for the nested hypervisor),
then VMLOAD/VMSAVE must operate on the L1 physical memory, which is only
possible by making L0 intercept these instructions.

Failure to do so allowed the nested guest to run VMLOAD/VMSAVE unintercepted,
and thus read/write portions of the host physical memory.

Fixes: 89c8a4984fc9 ("KVM: SVM: Enable Virtual VMLOAD VMSAVE feature")

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-16 09:48:37 -04:00
..
2021-08-13 03:20:18 -04:00
2021-03-18 15:31:53 +01:00
2021-06-28 15:40:51 -07:00
2021-03-18 15:31:53 +01:00