C free char* allocated on heap

Question

Is there a memory leak in the following code example as I have allocated memory on the heap for name which hasn't been freed? If I add free(person->name); before the free(person); line then I get a runtime error in VS "CRT detected that the application wrote to memory after end of heap buffer".

header.h:

#ifndef HEADER
#define HEADER

typedef struct person {
 char *name;
} Person;

#endif

source.c:

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

#define BUFFERSIZE 500

int main (int argc, char* argv[]){
 Person *person = NULL;
 char buffer[BUFFERSIZE];
 printf("Enter name\n");
 fgets(buffer, BUFFERSIZE, stdin);
 {
  char *name; 
  person = malloc(sizeof(Person));
  name = malloc(strlen(buffer));
  strcpy (name,buffer);
  person->name = name;
 }
 free(person); 
 return 0;
}

Thanks, Rob

Answer 1

strlen doesn't account for the null-terminator that strcpy adds, you'll need to "malloc(strlen(buffer)+1)"

Answer 2

Yes, the code has a memory leak.

The culprit is: name = malloc(strlen(buffer)); which should be
name = malloc(strlen(buffer)+1); to account for \0.

You should now be able to free person->name.

Answer 3

Yes. There is a memory leak.

You allocate a name buffer:

name = malloc(strlen(buffer));

and never deallocate it. Then when you deallocate the Person,

free(person); 

you lose your last pointer to that buffer, so you can never deallocate it.

The error message you are getting is a separate issue related to the length of the name buffer that you allocate being insufficient to include the null termination of the string you try to copy into it.