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

h()
{
        printf("Hello World\n");
        exit(1);
}
cp(char *str)
{
        char buff[16];
        strcpy(buff, str);
        printf("%s\n", buff);
}
int main(int argc, char* argv[])
{
        if(argc > 1)
        {
                cp(argv[1]);
        }
        return 0;
}



default:
$ gcc -o simple_overflow simple_overflow.c -fstack-protector




$ gcc -o simple_overflow-nosp simple_overflow.c -fno-stack-protector




$ objdump -d simple-overflow-nosp | grep '<h>'



$ ./simple_overflow $'12345123451234512345\x04\x84\x04\x08'



$ ./simple_overflow-nosp $'12345123451234512345\x04\x84\x04\x08'