CVE-2022-2196

A flaw was found in the KVM's Intel nested virtualization feature (nVMX). Since L1 and L2 shared branch prediction modes (guest-user and guest-kernel), KVM did not protect indirect branches in L1 from steering by a malicious agent in L2. This could allow a malicious nested guest to carry out Spectre v2 attacks against L1 due to a missing IBPB at VM-exit time.

Red Hat currently provides the nested virtualization feature as a Technology Preview. Nested virtualization is therefore unsupported for production use. For more information please refer to https://access.redhat.com/solutions/21101 and https://access.redhat.com/support/offerings/techpreview.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

This vulnerability can be mitigated by disabling the nested virtualization feature:

# modprobe -r kvm_intel
# modprobe kvm_intel nested=0