The department of defense (DOD) in the US has called for the contest in automatic attack and defense. The contest is a big challenge on the security development and called Cyber Grand Challenge (CGC). We consult to the competition rules and develop an automatic cyber reasoning system (CRS) to fulfill the goals. Our CRS combines with the techniques of fuzz testing, fault localization, and binary patch to build an automatic defense system. With the former efforts developed in the SQLab for automatic attack, we further integrate into a CRS for automatic attack and defense. Other than the sample problems in the CGC, we evaluate our systems in the binary patch capability on real programs. This work will be a preliminary study for potential participations on the future CGC.