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INT32-EX2. Checks for wraparound can be omitted when it can be determined at compile time that wraparound will not occur. As such, the following operations on unsigned integers require no validation:

• Operations operations on two compile-time constants.
• Operations operations on a variable and 0 (except division by 0, of course).
• Subtracting subtracting any variable from its type's maximum. For instance, any unsigned int may safely be subtracted from UINT_MAX.
• Multiplying multiplying any variable by 1.
• Divisiondivision, as long as the divisor is nonzero.
• Rightright-shifting any type maximum by any number smaller than the type size. For instance, UINT_MAX >> x is valid as long as x < sizeof(unsigned int).
• Leftleft-shifting 1 by any number smaller than the type size.

Risk Assessment

Integer wrap can lead to buffer overflows and the execution of arbitrary code by an attacker.

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