What is a dangling pointer?

A Dangling Pointer arises when you use the address of an object after its lifetime is over. This may occur in situations like returning addresses of the automatic variables from a function or using the address of the memory block after it is freed

{
 char *cp = NULL;
 /* ... */
 {
     char c;
     cp = &c;
 } /* c falls out of scope */        
   /* cp is now a dangling pointer */
}

To resolve dangling pointer issue:

#include 
{
  char *cp = malloc ( A_CONST );
  /* ... */
  free ( cp );      /* cp now becomes a dangling pointer */
  cp = NULL;        /* cp is no longer dangling */
  /* ... */
}