CVE-2026-64300 perf/aux: Fix page UAF in map_range()

In the Linux kernel, the following vulnerability has been resolved: perf/aux: Fix page UAF in maprange maprange reads rb-auxpages, rb-auxnrpages and rb-auxpgoff via perfmmaptopage while holding only event-mmapmutex. Those fields are serialized by rb-auxmutex, and mmapmutex is per event. Thus, two...