Protect add/remove node services from invalid instance ID (#41334)

homeassistant/components/ozw/services.py

@@ -111,6 +111,8 @@ class ZWaveServices:
         instance_id = service.data[const.ATTR_INSTANCE_ID]
         secure = service.data[const.ATTR_SECURE]
         instance = self._manager.get_instance(instance_id)
+        if instance is None:
+            raise ValueError(f"No OpenZWave Instance with ID {instance_id}")
         instance.add_node(secure)
 
     @callback
@@ -118,6 +120,8 @@ class ZWaveServices:
         """Enter exclusion mode on the controller."""
         instance_id = service.data[const.ATTR_INSTANCE_ID]
         instance = self._manager.get_instance(instance_id)
+        if instance is None:
+            raise ValueError(f"No OpenZWave Instance with ID {instance_id}")
         instance.remove_node()
 
     @callback