Abstract: A computer processor protects a protected word in computer readable memory by employing a canary word in the same buffer as the protected word that is protected by a secure bit and/or by employing a canary bit that directly protects the protected word. A bit setting module marks the protected word as tainted by setting the secure bit or canary bit in response to overwrite of the canary word and/or protected word, including overwrite resulting from overflow of the buffer. A validation module validates non-control data stored in the protected word every time the non-control data is used by a computer process by checking the secure bit of the canary word and/or by checking the canary bit of the protected word.