VMA Read Write Checking tool is a small security module for Linux-2.2.19 that only works on Intel based processors. The tool wraps execve() and checks to make sure that the caller does not call from a writeable memory segment. Since most local (and many remote) exploits call execve("/bin/sh",...) or similar from the stack (and environment, which is also located on the stack), it would prevent most standard exploits from working.
