Using programmer-written compiler extensions to catch security holes

Abstract

This paper shows how system-specific static analysis can find securityerrors that violate rules such as ``integers from untrusted sourcesmust be sanitized before use'' and ``do not dereference user-suppliedpointers.''In our approach, programmers write system-specificextensions that are linked into the compiler and check their code forerrors.We demonstrate the approach's effectiveness by using it tofind over 100 security errors in Linux and OpenBSD, over 50 of whichhave led to kernel patches.An unusual feature of our approach is theuse of methods to automatically detect when we miss code actions thatshould be checked.