CVE-2026-89917

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A race condition exists in the KVM arm64 component between VNCR TLB invalidation and the vcpu put() function during VNCR page unmapping. The issue arises because TLB invalidation occurs under the MMU lock, whereas vcpu put() does not. This creates a Time-of-Check to Time-of-Use (TOCTOU) pattern where the invalidation process checks the vncr tlb::cpu variable to determine if unmapping is necessary, while this cpu reset vncr fixmap() may unconditionally unmap the page if L1 VNCR MAPPED is set. This race can lead to a BUG ON() trigger or the execution of vncr fixmap(-1), resulting in system instability.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.