P-TAXI : enforcing memory safety with programmable tagged architecture

Abstract

Buffer overflow is a well-known problem that remains a threat to software security. With the advancement of code-reuse attacks and return-oriented programming (ROP), it becomes problematic to protect a program from being compromised. Several defenses have been developed in an attempt to defeat code-reuse attacks. However, there is still no solution that provides complete protection with low overhead. In this thesis, we improved TAXI, a ROP defense technique that utilizes a tagged architecture to prevent memory violations. Inspired by Programmable Unit for Metadata Processing (PUMP), we modified TAXI so that enforcement policies can be programmed by user-level code and called it P-TAXI (Programmable TAXI). We demonstrated that, by using P-TAXI, we were able to enforce memory safety policies, including return address protection, stack garbage collection, and memory compartmentalization. In addition, we showed that P-TAXI can be used for debugging and taint tracking.