Page History

...

long i = /* some expression that evaluates to the value 32767 */;
/* ... */
/* No test is necessary; i is known not to overflow. */
/* expression involving i + 1 */

Non-Compliant Code Example

Increasingly optimization techniques are being adopted that ignore the possibility of integer overflow to produce faster code. For example, in gcc versions 4.2 and later, code that performs length checks similar to the following:

char *buf;
int len = 1<<30;
/* ... */
if (buf+len < buf) { /* length check */
   /* perform some manipulation on len */
}

are optimized away; no object code to perform the check will appear in the resulting executable program \[[VU#162289|AA. C References#VU#162289]\]. 

Risk Assessment

Out of range integer values can result in fetches or stores from arbitrary memory locations and the execution of arbitrary code.

...

\[[Lions 96|AA. C References#Lions 96]\]
\[[VU#162289|AA. C References#VU#162289]\]

...

INT07-A. Use only explicitly signed or unsigned char type for numeric values      04. Integers (INT)       INT09-A. Ensure enumeration constants map to unique values