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Annex J of the C Standard [ISO/IEC 9899:20112024] states that it is undefined behavior if the "pointer passed to a library function array parameter does not have a value such that all address computations and object accesses are valid." (See undefined behavior 109108.)

In the following code,

int arr[5];
int *p = arr;

unsigned char *p2 = (unsigned char *)arr;
unsigned char *p3 = arr + 2;
void *p4 = arr;

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Depending on the library function called, an attacker may be able to use a heap or stack overflow vulnerability to run arbitrary code.

Automated Detection

ABV.GENERAL
ABV.ITERATOR
ABV.STACK
ABV.TAINTED
ABV.UNKNOWN_SIZEGENERAL.MULTIDIMENSION

CERT_C-ARR38-a
CERT_C-ARR38-b
CERT_C-ARR38-c
CERT_C-ARR38-d

Avoid overflow when reading from a buffer
Avoid overflow when writing to a buffer
Avoid buffer overflow due to defining incorrect format limits
Avoid overflow due to reading a not zero terminated string

419, 420

Partially supported

CERT C: Rule ARR38-C

Checks for:

• Mismatch between data length and size
• Invalid use of standard library memory routine
• Possible misuse of sizeof
• Buffer overflow from incorrect string format specifier
• Invalid use of standard library string routine
• Destination buffer overflow in string manipulation
• Destination buffer underflow in string manipulation

Rule partially covered.

2840, 2841, 2842, 2843, 2845, 2846,

2847, 2848, 2935, 2936, 2937, 2938

2840, 2841, 2842, 2843, 2845, 2846,

2847, 2848, 2935, 2936, 2937, 2938

Splint