CVE-2022-48763

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.17.0-rc1-syzkaller

Description The issue is related to the KVM (Kernel-based Virtual Machine) subsystem in the Linux kernel. Specifically, it involves the handling of nested virtualization and the System Management Mode (SMM) state. When userspace toggles the SMM state via KVM SET VCPU EVENTS or KVM SYNC X86 EVENTS, and then injects a System Management Interrupt (SMI), the vmx enter smm() function can overwrite vmx->nested.smm.vmxon, resulting in both vmxon and smm.vmxon being set to false, while other nVMX states remain allocated. This can lead to a memory leak and put the vCPU in an architecturally impossible state.

Recommendations To resolve this issue, update the Linux kernel to a version that includes the fix for this vulnerability. Specifically, versions prior to 5.17.0-rc1-syzkaller are affected. As a temporary workaround, consider disabling the KVM SET VCPU EVENTS and KVM SYNC X86 EVENTS events to prevent the toggling of the SMM state. However, this may have performance implications and should be carefully evaluated before implementation.