**Description**
An infinite loop can happen in routing if there is a catch all route with host name matching.
This problem is caused by the DFA matcher builder giving an incorrect exit destination to policies. Currently the exit destination is the catch all state, so the policy will transition to itself when there is no match. It will run again, transition to itself again, run again, etc. This causes the policy to run forever.
What should happen is the host name policy fails, it transitions to the final state with no candidates, and the route matcher does not match any endpoints. The browser is returned a 404 status.
**Customer Impact**
This problem shows up in this situation:
1. If a customer has configured a catch all route in their app
2. The catch all route has host matching
3. A browser makes a request to the server that matches the catch all route but doesn't match the host name
The route matcher will run forever, using up a threadpool thread. When threadpool threads are exhausted the server will stop responding.
**Regression?**
No.
**Risk**
Medium. The fix is simple but route matching is complex, and routing runs with every request.
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