Page History

...

Integer overflow is undefined behavior, so a compiled program can do anything, including going off to play the Game of Life. Furthermore, a compiler may perform optimizations that assume an overflow will never occur, which can easily yield unexpected results. Compilers can optimize away if statements that check whether an overflow occurred. See MSC15-C. Do not depend on undefined behavior for an example.

Verifiably in-range operations are often preferable to treating out-of-range values as an error condition because the handling of these errors has been repeatedly shown to cause denial-of-service problems in actual applications. The quintessential example is the failure of the Ariane 5 launcher, which occurred because of an improperly handled conversion error that resulted in the processor being shut down [Lions 1996].

A program that detects an integer overflow to be imminent may do one of two things: (1) signal some sort of error condition or (2) produce an integer result that is within the range of representable integers on that system. Some situations can be handled by an error condition, where an overflow causes a change in control flow (such as the system complaining about bad input and requesting alternative input from the user). Others are better handled by the latter option because it allows the computation to proceed and generate an integer result, thereby avoiding a denial-of-service attack. However, when continuing to produce an integer result in the face of overflow, the question of what integer result to return to the user must be considered.

...

...

CERT C++ Secure Coding Standard: INT08-CPP. Verify that all integer values are in range

ISO/IEC TR 24772 "FLC Numeric conversion errors"

...

[ISO/IEC 9899:2011] Section 6.2.5, "Types"

[Lions 1996]

...