Synopsis

A memory location is freed more than once on some paths but not on others.

Enabled by default

Yes

Severity/Certainty

Medium/Medium

Full description

There is a path through the code where a memory location is attempted to be freed after it has already been freed earlier. This will most likely cause an application crash on this path. This check is identical to MISRAC2012-Rule-22.2_b.

Coding standards

Code examples

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

#include <stdlib.h>
void example(void) {
    int *ptr = (int*)malloc(sizeof(int));
    free(ptr);
    if(rand() % 2 == 0)
    {
      free(ptr);
    }
}

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

#include <stdlib.h>
void example(void) {
    int *ptr = (int*)malloc(sizeof(int));
    if(rand() % 2 == 0)
    {
      free(ptr);
    }
    else
    {
      free(ptr);
    }
}