Null Pointer Dereference Mode Detection Based On Logic Judgment

Software security problems caused by null pointer dereference continue to emerge and bring great distress and loss to all aspects. In this paper, we apply static testing method to analyze and detect a kind of null pointer dereference.This paper present a method to detect null pointer dereference using judgment logical information. First, give some definitions and fault classifications about based on logic judgment to detect null pointer dereference fault(BLJDNPDF).Then, using method summary technology to extract indirect null judgment point and indirect pointer dereference point, define method summary’s contents, which contain method feature and post condition, do research on how to generate and transform method summary. Finally, using finite state machine to build model of BLJDNPDF, describe fault model description, and use state machine’s state change and method summary to complete BLJDNPDF detection.This paper is divided into five parts. The first part of this paper is to introduce the research background and the definition of BLJDNPDF. The second part describes the use of method summary technology to extract inter-procedure null judgment point and pointer dereference point, including the-abstract model of judgment logic method summary, algorithms to generate, transform method summary. The third part illustrates fault mode and uses the above method summary to achieve.fault detection. The fourth part is the experimental results and analysis, the fifth part summarizes and looks forward to future research work.