As far as I know, there's no way you can automatically kill it. Of course, you can setup billing / execution alerts, which would probably be very helpful in at least notifying you that there's a problem (I personally have an alert set up to notify me if my estimated charges are anything out of the ordinary).
A small anecdote: Lambda processes are _very_ cheap most of the time. When I was writing the initial version of this starter module, I accidentally threw the lambda into an infinite loop. It was triggered about 30k times within a minute or so and ended up costing around 13 cents if I remember correctly.