UCX shutdown sequence is crashing

[maor-lb]

We are trying to implement shudwon logic for listener but it seems we are hitting segfault with UCX 1.19

Our Shutdown Sequence:
// 1. Set application-level shutdown flag
callback_shutdown = true;

// 2. Drain all pending callbacks from progress queue
while (ucp_worker_progress(worker) > 0) { }

// 3. Destroy the listener
ucp_listener_destroy(listener);

But this does not prevent from new connection to arrive between 2 and 3 , which result in crash
What we saw is the ucp_cm_server_conn_request_cb can be called .

and in err flow it calls

err_reject:
      ucp_listener->conn_reqs--;
      status = uct_listener_reject(listener, conn_request);  // CRASH!
      // ^^^^^^^^ UCT listener was already destroyed by uct_listener_destroy()! 

it's not clear what is the sequence to solve this race