Thread: heap corruption while releasing the memory - triple pointer involved

Hey folks,
I was debugging a large code which I couldn't post here - so I wrote a prototype code just to handle the issue in my application. Please don't ask the logic or why I have written functions or that I could write it in other way. My issue is what is wrong with this piece of code and how to handle it? It is throwing me the error - "heap corruption" (in main function that i have jotted in red color line i.e. in free(ptr)). I am running it in Visual C++

the code is -

Code:

#include <stdio.h>
#include <malloc.h>
#include <stdlib.h>

void test_function(int ***);
int * fill();
int count();

int main()
{
	int **p=NULL;
	test_function(&p);
	free(*p);
	free(p); //THIS LINE IS THROWING THE ERROR
	system("pause");
	return 0;
}


void test_function(int ***p)
{
    int n=count();
    *p=(int **)malloc(n);
    int *temp=NULL;
    temp=fill();
    **p=temp;
 }

int * fill()
{
   int *temp=NULL;
   temp=(int *)malloc(sizeof(int));
   *temp=2;
   return temp;
}

int count()
{
	int cnt = 1;
	return cnt;
}

thanks and appreciate for any help

Code:

#include <stdio.h>
#include <stdlib.h>

void test_function(int ***);
int *fill();

int main()
{
	int **p=NULL;
	test_function(&p);
	free(*p);
	free(p);
	return 0;
}


void test_function(int ***p)
{
    *p = malloc(sizeof(**p));
    int *temp=NULL;
    temp=fill();
    **p=temp;
 }

int *fill()
{
   int *temp=NULL;
   temp=(int *)malloc(sizeof(int));
   *temp=2;
   return temp;
}

I took off the other function just to simplify the code, that wasn't the problem.
Can you see what was the problem?