Stack/Heap Overflow

// hack1.cpp : Defines the entry point for the console application.//#include <stdio.h>#include <string.h>#include <stdlib.h>#include <ctype.h>const size_t buffer_size = 16;const size_t buffer_ret_offset = 8 ;char*  buffer_data = "AAAABBBBCCCCDDD"; //"DEEEEFFFFGGGG";void print_mem(unsigned char* mem, const int len, const int bytes_in_line = 8);void stack_func(char* data);void heap_func(char* data);int main(int argc, char* argv[]){	stack_func(buffer_data); // 28 + 1	heap_func(buffer_data); // 28 + 1	system("pause");	return 0;}void stack_func(char* data){	char buffer[buffer_size];  // Staticky vytvoreny buffer	printf("stack_func(data = 0x%p) - buffer(STACK %d Bytes) = 0x%p\n",data,buffer_size,&buffer);		strcpy(buffer,data);	print_mem((unsigned char*)&buffer+buffer_size+buffer_ret_offset,4);	buffer[buffer_size+buffer_ret_offset+0] = 'A';	buffer[buffer_size+buffer_ret_offset+1] = 'A';	buffer[buffer_size+buffer_ret_offset+2] = 'A';	buffer[buffer_size+buffer_ret_offset+3] = 'A';	print_mem((unsigned char*)&buffer+buffer_size+buffer_ret_offset,4);}void heap_func(char* data){	char* buffer = (char*) malloc(buffer_size); // Dynamicky vytvoreny model	printf("heap_func(data = 0x%p) - buffer(HEAP %d Bytes) = 0x%p\n",data,buffer_size,buffer);	strcpy(buffer,data);	print_mem((unsigned char*)buffer,2*buffer_size);	free(buffer);}void print_mem(unsigned char* mem, const int len, const int bytes_in_line){	printf("MEMORY DUMP BEGIN - 0x%p (%d Bytes)\n",mem, len);	for(int i = 0; i < (len/bytes_in_line)+1; i++)  // Prizpusobene zpracovani po radcich	{		for(int j = 0; j < bytes_in_line && (i*bytes_in_line+j < len); j++)		{			int c = (int)mem[i*bytes_in_line+j];			if(isprint(c))			{				printf("%c (0x%02X)  ",mem[i*bytes_in_line+j],mem[i*bytes_in_line+j]);			}			else			{				printf("%? (0x%02X)  ",mem[i*bytes_in_line+j]);			}					}	}	printf("\nMEMORY DUMP END\n");}