CVE-2026-31592

A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem. A local user could exploit a concurrency issue by failing to properly protect the sev_mem_enc_register_region() function with the kvm->lock. This can lead to an unstable state if KVM initialization fails, resulting in a general protection fault and a null-pointer dereference. The most important consequence is a denial of service, causing the system to crash.

sev_mem_enc_register_region() is now fully serialized with kvm->lock, closing races in SEV memory region registration. Red Hat recommends patched KVM kernels for SEV deployments.

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.