Enhancing the Security of Parallel Programs via Reducing Scheduling Space

Parallel programs face a new security problem - concurrency vulnerability, which is caused by a special thread scheduling instead of inputs. In this paper, we propose to automatically fix concurrency vulnerabilities by reducing thread scheduling space. Our method is based on two observations. First, most concurrency vulnerabilities are caused by atomicity violation errors. Second, reducing thread scheduling space does not harm the correctness of the original program. We designed a prototype runtime system shield using deterministic multithreading techniques. Shield is designed to transparently run parallel programs and schedule threads in large instruction blocks to prevent atomicity violation at best effort. In case some concurrency vulnerabilities cannot be fixed by shield´s scheduling reducing scheme, we also provide a remedy strategy by integrating shield with record&replay function, so that it can help programmers to analyze attacker´s behavior for manually fixing.