An Efficient Use-after-Free Mitigation Approach via Static Dangling Pointer Nullification

UAF (use-after-free) is one of the most severe program vulnerabilities, caused by dangling pointers. Existing vulnerability mitigation approaches either attempt to block possible exploitation without fixing the root cause problem, or identify and remove dangling pointers with huge runtime overhead. In this paper, we present SDPN (Static Dangling Pointer Nullification) to defeat use-after-free vulnerability by eliminating dangling pointers filtered in multiple stages during compilation time. We implement a prototype of SDPN and evaluate it using realworld CVE vulnerabilities, and the results show that SDPN can effectively protect programs from use-after-free vulnerability. We also test SDPN using SPEC 2006 and the experimental results demonstrate that the time overhead introduced by SDPN is almost negligible, i.e., <1%.