Add a door stop to your interior garage door
Time: 5 Minutes Cost: $5 Difficulty: Easy
To see more: http://magentaandlime.blogspot.com/2013/01/installing-door-stop.html

In addition, if you ever have a claim on your insurance policy because of a fire issue in your garage, even if the door was closed you risk a cancellation of the policy.
Your better off with a brick enclosed in a cloth bag or something that once it moves will not risk preventing the door from staying open. But any permanently mounted on the door stopper is a no-no.