ARR-inv-index-ptr
Synopsis
A pointer to an array is used outside the array bounds.
Enabled by default
Yes
Severity/Certainty
High/High

Full description
A pointer to an array is used outside the array bounds. This will cause an invalid memory access, and might be a serious security risk. The application might also crash. This check is identical to MISRAC++2008-5-0-16_e, MISRAC2012-Rule-18.1_c, CERT-ARR30-C_c.
Coding standards
- CERT ARR30-C
Do not form or use out of bounds pointers or array subscripts
- CWE 119
Improper Restriction of Operations within the Bounds of a Memory Buffer
- CWE 120
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
- CWE 121
Stack-based Buffer Overflow
- CWE 122
Heap-based Buffer Overflow
- CWE 124
Buffer Underwrite ('Buffer Underflow')
- CWE 126
Buffer Over-read
- CWE 127
Buffer Under-read
- CWE 129
Improper Validation of Array Index
- MISRA C:2012 Rule-18.1
(Required) A pointer resulting from arithmetic on a pointer operand shall address an element of the same array as that pointer operand
- MISRA C++ 2008 5-0-16
(Required) A pointer operand and any pointer resulting from pointer arithmetic using that operand shall both address elements of the same array.
Code examples
The following code example fails the check and will give a warning:
void example(void) {
int arr[10];
int *p = arr;
p[10];
}
The following code example passes the check and will not give a warning about this issue:
void example(void) {
int arr[10];
int *p = arr;
p[9];
}