At first sight, it seemed to be exactly what we were looking for. F2fs support for grub2 pending implemented features. This training is focused on exploitation of different windows kernel mode vulnerabilities ranging from pool overflow to use after free. While processing ioctls, the fuzzer will spoof those ioctls conforming to conditions specified in the configuration file. Linus torvalds says targeted fuzzing is improving linux. We leverage static analysis to compose correctlystructured input in the userspace to explore kernel drivers. The monitoring mode allows logging of irps, optionally including their hex dumps, into a file andor a console. In this paper, we present difuze, an interfaceaware fuzzing tool to automatically generate valid inputs and trigger the execution of the kernel drivers. Sep 09, 2015 ioctl fuzzer is a tool designed to automate the task of searching vulnerabilities in windows kernel drivers by performing fuzz tests on them. Like the power framework delay fuzzing option, the kernel synchronization delay fuzzing option uses an algorithm that provides help improve the chances of finding errors in drivers. Each interface will require a different method to provide the fuzzed data.
I am aware of the prevailing opinion that fuzzing talks without bugs suck, by definition. Oct 16, 2017 linus torvalds release notification for linux 4. We utilize a hypervisor and intels processor trace pt technology. Windows kernel fuzzing framework easily scalable reproducible bsod modular and adaptable friendly internal competition windows kernel fuzzing by nils platform agnostic kernel fuzzing by james loureiro and georgi geshev. With a kernel driver, each interface type can be interesting to test. Note this option is available starting with windows 8. Ioctlbf is just a small tool proof of concept that can be used to search vulnerabilities in windows kernel drivers by performing two tasks. Scanning for valid ioctls codes supported by drivers, generationbased ioctl fuzzing. Announcing the fifth release candidate for the linux kernel version 4. Evolutionary kernel fuzzing black hat usa 2017 richard johnson. You can also use the kernel synchronization delay fuzzing that is included with driver verifier. The mutation simply consisted in replacing this byte by a random one. Syzkaller 1 starts to support usb fuzzing recently and has already found over 80 bugs within the linux kernel 2.
Interface recovery the interface recovery mechanism is based on llvm analysis passes. This patch addressed multiple privately reported vulnerabilities in win32k. Kernel synchronization delay fuzzing windows drivers. Important this article contains information that shows you how to help lower security settings or how to turn off security features on a computer. When the option is selected, driver verifier inserts random delays at various points in the threads. Iospy and ioattack are tools that perform ioctl and wmi fuzz tests on kernelmode drivers. Jun 27, 2016 this post series is about how we used atscale fuzzing to discover and report a total of 16 vulnerabilities in the handling of truetype and opentype fonts in the windows kernel during the last year. Before you make these changes, we recommend that you evaluate the risks that are associated with implementing this workaround in your particular environment. Using driver verifier manager start driver verifier manager. This training is the advanced version of windows kernel exploitation course focused on exploitation of different windows kernel mode vulnerabilities on latest patched version of windows 10 version 1703. Fuzzer for linux kernel drivers tested on ubuntu 14. We will understand pool manager internals in order to groom kernel pool memory for reliable exploitation of poolbased vulnerabilities. Resource windows kernel fuzzers and tools chiheb chebbi. This solution is based on the remote kernel debugger system, so there are two machines.
Vulnerabilities in windows kernelmode driver could allow remote code execution. Now that we know how to compile the driver, we also have to look at how to load it into the kernel. Almost every fuzzing expert whom i talked to has started to apply their fuzzing techniques to usb because of the highsecurity impact and potential volume of vulnerabilities due to the complexity of usb itself. Fuzzing kernel drivers with interface awareness black hat. Furthermore, if a process fuzzes its own kernel, a kernel crash highly impacts the performance of the fuzzer as the os needs to reboot. An advantage of this tool is that it does not rely on captured ioctls. Finding kernel race bugs through fuzzing request pdf.
In june 2016 we opensourced windows driver for intel processor trace. Guaranteed real bugs, and we have a poc to go with it. Jun 21, 2017 windows kernel programming tutorial 1 setting up environment part 1. Windows kernel programming tutorial 1 setting up environment part 1. The fuzzers own driver hooks ntdeviceiocontrolfile in order to take control of all ioctl requests throughout the system. Oct 17, 2017 announcing the fifth release candidate for the linux kernel version 4. Based on these features, this is the novel fuzzing architecture of lldbfuzzer. We emulated a usb mass storage device and dumped the traffic exchanged. Syzfuzzer is the main executable for driving the fuzzing process inside the guest vm. Linus torvalds lauds fuzzing for improving linux security. Mar 15, 2012 the fuzzing process actually follows the following steps. In our previous research, we used winafl to fuzz userspace applications running on windows, and found over 50 vulnerabilities in adobe reader and microsoft edge for our next challenge, we decided to go after something bigger. And, in his talk called efficient unit test and fuzz tools for kernellibc porting, bamvor will share some ways to improve the trinity fuzzing tool.
By using these tools, you can ensure that drivers ioctl and wmi code validate data buffers and buffer lengths correctly. A wellknown kernel fuzzing tool is syzkaller 3, which has found hundreds of real bugs in linux device drivers 4. Kernel fuzzing model each syscall so we know how to call it and what to pass as arguments this is very hard for ioctls recovering this interface requires lots of manual effort, and as such, ioctls are often neglected when fuzzing. Iospy and ioattack are tools that perform ioctl and wmi fuzz tests on kernel mode drivers. At a high level some similarities exist among drivers. To run this script you should know at least one process which sends ioctl to your target device you are fuzzing. Select select individual settings from a full list. Windows kernel fuzzing kernelfuzzer 2016 james loureiro and georgi geshev windows system api fuzzer techniques type aware api fuzzing manual definition of generators pertype pregenerated handle tables outputs c code for each testcase to repro after crash. This post series is about how we used atscale fuzzing to discover and report a total of 16 vulnerabilities in the handling of truetype and opentype fonts in the windows kernel during the last year. Mar 16, 2014 inmemory kernel driver ioctl fuzzing using python im sharing one of my kernel driver ioctl fuzzer which operates completely from user land. Apr 12, 20 when we build an export driver, we must place it in the c. How to temporarily deactivate the kernel mode filter. Windows 8 and later versions when this option is active, driver verifier applies a set of device driver interface ddi rules that check for the proper interaction between a driver and the kernel interface of the operating system.
In order to enter the kernel right from an application, one has to set up call gate descriptor in global descriptor table gdt, so that an application can enter the kernel via the call gate. Kernel drivers are programs written against windows nts native api rather than the win32 subsystems api and which execute in kernel mode on the underlying hardware. Bamvor jian zhang in his experience, the correctness of arguments passing between the c library and core kernel code is a common problem. Dec 12, 2011 besides the fuzzing functionality, monitoring mode is also available with the tool. Many driver fuzzing approaches 5 7 are based on syzkaller. For every driver the tool identifies all the ioctl entry points, aswellasthecorrespondingstructures,anddevicefilenames. One of the unique challenges of driver fuzzing is that each driver is different.
We will cover basics of windows kernel internals and handson. Google fuzzer finds ton of holes in kernels usb subsystem. In the previous part of the article, weve explained how to compile the windows kernel driver. Windows graphics driver fuzzing d3dkmtescape entry point for internal graphics functionality each driver implements a proprietary format for pdata a few header fields and command data. You can make these changes to work around a specific problem. Inmemory kernel driverioctlfuzzing using python im sharing one of my kernel driver ioctl fuzzer which operates completely from user land. To implement a windows kernel fuzzer fuzzes on the current state logs testcases reproducible and minimisable extensible and modular core kernel, win32k and other drivers is able to run automated at a large scale and most importantly finds a lot of vulns many implementation ideas borrowed from browser fuzzing. While processing ioctls, the fuzzer will spoof those ioctls conforming to conditions specified in the. My first question is simple is fuzzing the linux kernel possible. Loading the windows kernel driver infosec resources. He has authored hacksys extreme vulnerable driver hevd which has. We will cover basics of windows kernel internals and handson fuzzing of windows kernel mode drivers. This talk will present an architecture for fuzzing the windows kernel and.
The fuzzing process actually follows the following steps. Every step of interface recovery are written as individual passes. I have heard of people fuzzing plenty of protocols etc. In our previous research, we used winafl to fuzz userspace applications running on windows, and found over 50 vulnerabilities in adobe reader and microsoft edge. Level software exploitation both in user and kernel mode, vulnerability research, reverse engineering, hybrid fuzzing, and program analysis. Kinda dirty code, but worked for me to find several bugs in windows drivers. Evolutionary kernel fuzzing black hat usa 2017 richard. Then, we decided to fuzz the configuration descriptor, and particularly the bnumendpoints field. Intro to windows kernel security development ncc group.
Display driver nvidia windows kernel mode driver, version 186. This means that a driver needs to be able to deal with switching virtual memory contexts between processes, and needs to be written to be incredibly stable because kernel. Jul 17, 2019 syzkaller 1 starts to support usb fuzzing recently and has already found over 80 bugs within the linux kernel 2. Then the agent sends 5 the inputs to a target kernel component. Ioctl fuzzer is a tool designed to automate the task of searching vulnerabilities in windows kernel drivers by performing fuzz tests on them. The fuzzer s own driver hooks ntdeviceiocontrolfile in order to take control of all ioctl requests throughout the system. In this paper, we approach the problem of coverageguided kernel fuzzing in an osindependent and hardwareassisted way. Vulnerabilities in windows kernel mode driver could allow remote code execution. Entering the kernel without a driver and getting interrupt. However, once usermode code is not allowed to access gdt, above mentioned authors used a kernelmode driver in order to set up call gate descriptor. Besides the fuzzing functionality, monitoring mode is also available with the tool. This is a project from back in tha dayz, in 20112012.
Syzkaller has its own syntax to describe programs, syscalls. Using driver verifier to identify issues with windows. My aim is to both statically audit as well as fuzz the kernel targeting version 3. Improving fuzzing tools for more efficient kernel testing. Windows kernel exploitation advanced power of community. Hardwareassisted feedback fuzzing for os kernels sergej schumilo. Display driver nvidia windows kernel mode driver, version. Even with a recovered interface, it can be very hard to generate. The ddi compliance checking option is implemented by using a kernelmode library, called verifierext. Windows kernel fuzzing framework easily scalable reproducible bsod modular and adaptable friendly internal competition windows kernel fuzzing by nils platform agnostic kernel fuzzing by james loureiro and georgi geshev different implementation find different vulnerabilities.
Windows driver security and fuzzing resources mwri fuzzing the. Dec 28, 2017 syzbot as the automation driver for syzkaller has managed to report around 200 kernel bugs over the past two months. Also, the driver is only loaded into the kernel when were using it from another drivers. By doing this, you avoid buffer overruns that can lead to system instability. Fuzzing the windows kernel may 6, 2020 research by. The fuzzer focuses on windows kernel objects and the relationship with different objects.