Reminds me of a hang in the Settings UI that was because it would get stuck on an RPC call to some service.

Why was the service holding things up? Because it was waiting on acquiring a lock held by one of its other threads.

What was that other thread doing? It was deadlocked because it tried to recursively acquire an exclusive srwlock (exactly what the docs say will happen if you try).

Why was it even trying to reacquire said lock? Ultimately because of a buffer overrun that ended up overwriting some important structures.