Local privilege escalation via taprio schedule race

Use-after-free in the Linux taprio scheduler from 5.2 allows local users to corrupt kernel memory through racing schedule changes. In taprio_change(), advance_sched() can replace and free the administrative schedule while parsing occurs outside the undersized current_entry_lock critical section, leaving admin dangling. A user with namespace-scoped CAP_NET_ADMIN can control the race without user interaction, enabling kernel-memory disclosure, writes, privilege escalation, or a kernel panic.