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IAR Embedded Workbench for Arm 9.70.x

MISRAC++2008-5-0-16_d

In this section:
Synopsis

(Required) A pointer operand and any pointer resulting from pointer arithmetic using that operand shall both address elements of the same array.

Enabled by default

Yes

Severity/Certainty

High/High

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Full description

An array access might be out of bounds for some execution paths. This check is identical to ARR-inv-index-pos, MISRAC2012-Rule-18.1_b, CERT-ARR30-C_b.

Coding standards
CERT ARR33-C

Guarantee that copies are made into storage of sufficient size

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 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

Code examples

The following code example fails the check and will give a warning:

int cond;

int main(void)
{
  int a[7];
  int x;

  if (cond)
    x = 3;
  else
    x = 20;

  a[x] = 0;  //x may be set to 20 in line 11
             //but a only has an interval of [0,6]
  return 0;
}

The following code example passes the check and will not give a warning about this issue:

int cond;

int main(void)
{
  int a[25];
  int x;

  if (cond)
    x = 3;
  else
    x = 20;

  a[x] = 0;  //here, both possible values of
             //x are in the interval [0,24]
  return 0;
}