Datasets:
Devilishcode
/
hacking

Dataset card Data Studio Files
xet
 Community
text
stringlengths
0
1.99k
efforts to harden the platform, IOKit continues to be a frequent source of
vulnerabilities. Identifying which methods are accessible from user space
is a first step for vulnerability research in this area. It enables the
accurate enumeration of all available endpoints, ensuring complete coverage
during fuzz testing.
This article outlines a structured methodology for mapping the IOKit
external methods exposed to user space. By employing a combination of
static analysis and runtime enumeration, we can identify accessible
interfaces, pinpoint potential attack vectors, and establish a solid
foundation for effective fuzzing. Our goal is to enhance the precision and
effectiveness of IOKit vulnerability research.
This guide focuses solely on "external methods," but it is important to
note that IOKit drivers also provide other communication channels, such as:
- Properties: For reading and writing driver configuration values
- Notifications: For receiving asynchronous events from the driver
- Shared memory: For efficient large data transfers
- External traps: A legacy method (use external methods instead)
- Shared Data Queue: For bidirectional queued data transfer
- IOStream: For continuous data streaming
While this guide does not cover these additional channels, familiarizing
yourself with the material presented here will help improve your
understanding of them.
============================
--[ 1 - IOKit Interface Fundamentals
============================================================================
The first part of the guide teaches about the main components of the
IOKit. It introduces IOKit kernel space components and how to interact with
them from User Space.
=====================
--[ 1.0 - Introduction to IOKit
============================================================================
IOKit is a framework in macOS that allows user-space applications to
interact with hardware devices, forming part of the XNU kernel. It provides
C++ classes and APIs for device drivers, abstracting hardware for easier
management. The framework is documented extensively in Apple's IOKit
Fundamentals[0].
========
--[ 1.1 - Registry
============================================================================
Apple's IOKit maintains an IORegistry[1] of all devices in the system,
organized as a tree structure. Each node (I/O Service instance) in this
tree represents a device, driver, or attachment point, and the
relationships between nodes reflect how devices are physically or logically
connected. Here is an example of device family tree where a Mac machine has
a USB port, a USB hub is connected to that port, and both a keyboard and
mouse are plugged into the hub:
````````````````````````````````````````````````````````````````````````````
[Mac]
|
+-- [USB Port]
|
+-- [USB Hub]
|
+-- Keyboard
+-- Mouse
````````````````````````````````````````````````````````````````````````````
Each item ("Mac", "USB Port", etc.) is an IORegistryEntry[2] object (or an
object derived from IORegistryEntry), forming the hierarchical structure of
the IORegistry.
======
--[ 1.1.1 - Planes
============================================================================
IOKit's IORegistry organizes all services in a tree structure that can
be viewed through different "planes". Each plane[3] represents a distinct
type of relationship or hierarchy among the same set of objects. The
previous example of the USB family tree illustrates the Service plane. It
should be the primary plane for mapping the attack surface in IOKit during
vulnerability research, as it serves as the root plane. Focusing on other
planes may result in missing services.
========
--[ 1.1.2 - Services
============================================================================
The IOService[4] is the base class for all drivers in IOKit,
representing
hardware devices, virtual devices, or kernel-only system services. These
services operate with full kernel privileges and direct hardware access.
User space applications cannot directly instantiate, access, or call
methods on I/O service objects.
======
--[ 1.1.3 - Driver
============================================================================
Drivers are classes that inherit from superclasses, all ultimately
deriving from the IOService class. For example, MyUSBDriver inherits from
IOService, allowing dynamic interaction with it as an IOService object:
````````````````````````````````````````````````````````````````````````````
class MyUSBDriver : public IOService {
public:
virtual bool init(OSDictionary *dictionary = NULL) override;
virtual bool start(IOService *provider) override;
virtual void stop(IOService *provider) override;
IOReturn sendCommand(uint8_t cmd, uint32_t value);