Integer overflow: Difference between revisions

Revision as of 20:33, 16 August 2007

Revision as of 09:17, 5 September 2007

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==Security ramifications==

In some situations a program may make the assumption that a variable always contains a positive value. If the variable has a signed integer type an overflow can causescause its value to wrap and become negative, violating the assumption contained in the program and perhaps leading to unintended behavior. Similarly, subtracting from a small unsigned value may cause it to wrap to a large positive value which may also be an unexpected behavior.

Some languages, such as [[Lisp (programming language)|Lisp]] and [[Ada (programming language)|Ada]], provide mechanisms that, if used, result in accidental overflow triggering an exception condition (interrupt?). Many languages do not support such functionality.