Linux x86/CPU/AMD - INVLPGB on Zen 2 (Cyan Skillfish): Using broadcast TLB invalidation (INVLPGB) on affected Zen 2

Impact

Using broadcast TLB invalidation (INVLPGB) on affected Zen 2 parts oopses the system. TLB invalidation is core memory-management machinery, so a defect here is both a stability problem and, in principle, a correctness problem for the mappings that separate address spaces.

Who can reach it

Local, triggered by normal kernel memory management on affected silicon rather than by an attacker.

What to do

Fixed in the Linux kernel by disabling INVLPGB on affected parts. Distro kernel update plus reboot.

References