Stack Four
Soal
/*
* phoenix/stack-four, by https://exploit.education
*
* The aim is to execute the function complete_level by modifying the
* saved return address, and pointing it to the complete_level() function.
*
* Why were the apple and orange all alone? Because the bananna split.
*/
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define BANNER \
"Welcome to " LEVELNAME ", brought to you by https://exploit.education"
char *gets(char *);
void complete_level() {
printf("Congratulations, you've finished " LEVELNAME " :-) Well done!\n");
exit(0);
}
void start_level() {
char buffer[64];
void *ret;
gets(buffer);
ret = __builtin_return_address(0);
printf("and will be returning to %p\n", ret);
}
int main(int argc, char **argv) {
printf("%s\n", BANNER);
start_level();
}
Solusi