In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix deadlock between rcu_tasks_trace and event_mutex.

Fix the following deadlock:
CPU A
_free_event()
  perf_kprobe_destroy()
    mutex_lock(&event_mutex)
      perf_trace_event_unreg()
        synchronize_rcu_tasks_trace()

There are several paths where _free_event() grabs event_mutex
and calls sync_rcu_tasks_trace. Above is one such case.

CPU B
bpf_prog_test_run_syscall()
  rcu_read_lock_trace()
    bpf_prog_run_pin_on_cpu()
      bpf_prog_load()
        bpf_tracing_func_proto()
          trace_set_clr_event()
            mutex_lock(&event_mutex)

Delegate trace_set_clr_event() to workqueue to avoid
such lock dependency.

https://git.kernel.org/stable/c/255cbc9db7067a83713fd2f4b31034ddd266549a

https://git.kernel.org/stable/c/45286680b385f2592db3003554872388dee66d68

https://git.kernel.org/stable/c/4580f4e0ebdf8dc8d506ae926b88510395a0c1d1

https://git.kernel.org/stable/c/b5a528a34e1f613565115a7a6016862ccbfcb9ac

https://git.kernel.org/stable/c/c5c833f6375f8ecf9254dd27946c927c7d645421