Electric Fence (efence) is an open-source library to detect buffer overruns and under-runs in C programs. Here you can find a further development of the original from Bruce Perens. This version includes

* a port to MS Windows® NT/2K/XP systems/compiler
* extensions for finding memory-leaks
* support for C++

Electric Fence (efence) stops your program on the exact instruction that overruns (or underruns) a malloc() memory buffer. GDB will then display the source-code line that causes the bug.

It works by using the virtual-memory hardware to create a red-zone at the border of each buffer - touch that, and your program stops. Catch all of those formerly impossible-to-catch overrun bugs that have been bothering you for years.