CVE-2023-30456

A flaw was found in the KVM's Intel nested virtualization feature (nVMX). The effective values of the guest CR0 and CR4 registers could differ from those included in the VMCS12. In rare circumstances (i.e., kvm_intel module loaded with parameters nested=1 and ept=0) this could allow a malicious guest to crash the host system, causing a denial of service.

It was discovered that the Broadcom FullMAC USB WiFi driver in the Linux kernel did not properly perform data buffer size validation in some situations. A physically proximate attacker could use this to craft a malicious USB device that when inserted, could cause a denial of service (system crash) or possibly expose sensitive information. Reima Ishii discovered that the nested KVM implementation for Intel x86 processors in the Linux kernel did not properly validate control registers in certain situations. An attacker in a guest VM could use this to cause a denial of service (guest crash). Various other issues were also addressed.