Red Hat Technology and Roadmap

RHEL5 SELinux Enhancements  ExecShield This enhancement can prevent any memory that was writable from becoming executable. This prevents an attacker from writing his code into memory and then executing it  Stack Smashing protection (Canary values) The system will place a canary value at a randomized point above the stack. This canary value is verified during normal operation. If the stack has been smashed, the canary value will have been overwritten, indicating that the stack has been smashed. This is a method to detect buffer overflows early.  FORTIFY_SOURCE GCC option When the compiler knows the size of a buffer, functions operate on the buffer to make sure it will not overflow at runtime. This works to help catch format string flaws as well as buffer overflows. 30