Free(): invalid pointer in C program

Question

I am executing following C program and getting runtime error as "free(): Invalid Pointer"

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

static void freeArgs(char** args);

int main()
{
    char** argv = calloc(4, 10);
    int  argc = 0;

    argv[argc++]="yogita";
    argv[argc++] ="negi";
    argv[argc] = NULL;
    freeArgs(argv);
    return 0;
}

static void freeArgs(char** args)
{
    char** af = args;
    for (; *af; af++)
        free(*af);
    free(args);
}

Can anyone suggest me the solution?

Answer 1

free(*af);

tries to free memory that was not allocated through malloc/calloc:

argv[argc++]="yogita";

"yogita" is a string literal, thus not dynamically allocated. You can't free its memory.