Contributing to Linux Kernel security by pperego

Description

A couple of weeks ago, I found this blog post by Gustavo Silva, a Linux Kernel contributor.

I always strived to start again into hacking the Linux Kernel, so I asked Coverity scan dashboard access and I want to contribute to Linux Kernel by fixing some minor issues.

I want also to create a Linux Kernel fuzzing lab using qemu and syzkaller

Goals

1. Fix at least 2 security bugs
2. Create the fuzzing lab and having it running

The story so far

• Day 1: setting up a virtual machine for kernel development using Tumbleweed. Reading a lot of documentation, taking confidence with Coverity dashboard and with procedures to submit a kernel patch
• Day 2: I read really a lot of documentation and I triaged some findings on Coverity SAST dashboard. I have to confirm that SAST tool are great false positives generator, even for low hanging fruits.
• Day 3: Working on trivial changes after I read this blog post: https://www.toblux.com/posts/2024/02/linux-kernel-patches.html. I have to take confidence with the patch preparation and submit process yet.
  • First trivial patch sent: using strtruefalse() macro instead of hard-coded strings in a staging driver for a lcd display
  • Fix for a dereference before null check issue discovered by Coverity (CID 1601566) https://scan7.scan.coverity.com/#/project-view/52110/11354?selectedIssue=1601566
• Day 4: Triaging more issues found by Coverity.
  • The patch for CID 1601566 was refused. The check against the NULL pointer was pointless so I prepared a version 2 of the patch removing the check.
  • Fixed another dereference before NULL check in iwlmvmparsewowlaninfo_notif() routine (CID 1601547). This one was already submitted by another kernel hacker :(
• Day 5: Wrapping up. I had to do some minor rework on patch for CID 1601566. I found a stalker bothering me in private emails and people I interacted with me, advised he is a well known bothering person. Markus Elfring for the record.

• Wrapping up: being back doing kernel hacking is amazing and I don't want to stop it. My battery pack is completely drained but changing the scope gave me a great twist and I really want to feel this energy not doing a single task for months.

  I failed in setting up a fuzzing lab but I was too optimistic for the patch submission process.

The patches

1

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Create DRM drivers for VESA and EFI framebuffers by tdz

Description

We already have simpledrm for firmware framebuffers. But the driver is originally for ARM boards, not PCs. It is already overloaded with code to support both use cases. At the same time it is missing possible features for VESA and EFI, such as palette modes or EDID support. We should have DRM drivers for VESA and EFI interfaces. The infrastructure exists already and initial drivers can be forked from simpledrm.

Goals

• Initially, a bare driver for VESA or EFI should be created. It can take functionality from simpledrm.
• Then we can begin to add additional features. The boot loader can provide EDID data. With VGA hardware, VESA can support paletted modes or color management. Example code exists in vesafb.

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Modularization and Modernization of cifs.ko for Enhanced SMB Protocol Support by hcarvalho

Creator:
Enzo Matsumiya ematsumiya@suse.de @ SUSE Samba team
Members:
Henrique Carvalho henrique.carvalho@suse.com @ SUSE Samba team

Description

Split cifs.ko in 2 separate modules; one for SMB 1.0 and 2.0.x, and another for SMB 2.1, 3.0, and 3.1.1.

Goals

Primary

Start phasing out/deprecation of older SMB versions

Secondary

• Clean up of the code (with focus on the newer versions)
• Update cifs-utils
• Update documentation
• Improve backport workflow (see below)

Technical details

Ideas for the implementation.

• fs/smb/client/{old,new}.c to generate the respective modules
  • Maybe don't create separate folders? (re-evaluate as things progresses!)
• Remove server->{ops,vals} if possible
• Clean up fs_context.* -- merge duplicate options into one, handle them in userspace utils
• Reduce code in smb2pdu.c -- tons of functions with very similar init/setup -> send/recv -> handle/free flow
• Restructure multichannel
  • Treat initial connection as "channel 0" regardless of multichannel enabled/negotiated status, proceed with extra channels accordingly
  • Extra channel just point to "channel 0" as the primary server, no need to allocate an extra TCPServerInfo for each one
• Authentication mechanisms
  • Modernize algorithms (references: himmelblau, IAKERB/Local KDC, SCRAM, oauth2 (Azure), etc.

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FizzBuzz OS by mssola

Project Description

FizzBuzz OS (or just fbos) is an idea I've had in order to better grasp the fundamentals of the low level of a RISC-V machine. In practice, I'd like to build a small Operating System kernel that is able to launch three processes: one that simply prints "Fizz", another that prints "Buzz", and the third which prints "FizzBuzz". These processes are unaware of each other and it's up to the kernel to schedule them by using the timer interrupts as given on openSBI (fizz on % 3 seconds, buzz on % 5 seconds, and fizzbuzz on % 15 seconds).

This kernel provides just one system call, write, which allows any program to pass the string to be written into stdout.

This project is free software and you can find it here.

Goal for this Hackweek

• Better understand the RISC-V SBI interface.
• Better understand RISC-V in privileged mode.
• Have fun.

Resources

• SBI v2.0 ratified specification
• Blog post on SBI
• mssola/fbos

Results

The project was a resounding success Lots of learning, and the initial target was met.

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RISC-V emulator in GLSL capable of running Linux by favogt

Description

There are already numerous ways to run Linux and some programs through emulation in a web browser (e.g. x86 and riscv64 on https://bellard.org/jslinux/), but none use WebGL/WebGPU to run the emulation on the GPU.

I already made a PoC of an AArch64 (64-bit Arm) emulator in OpenCL which is unfortunately hindered by a multitude of OpenCL compiler bugs on all platforms (Intel with beignet or the new compute runtime and AMD with Mesa Clover and rusticl). With more widespread and thus less broken GLSL vs. OpenCL and the less complex implementation requirements for RV32 (especially 32bit integers instead of 64bit), that should not be a major problem anymore.

Goals

Write an RISC-V system emulator in GLSL that is capable of booting Linux and run some userspace programs interactively. Ideally it is small enough to work on online test platforms like Shaderoo with a custom texture that contains bootstrap code, kernel and initrd.

Minimum:

riscv32 without FPU (RV32 IMA) and MMU (µClinux), running Linux in M-mode and userspace in U-mode.

Stretch goals:

FPU support, S-Mode support with MMU, SMP. Custom web frontend with more possibilities for I/O (disk image, network?).

Resources

RISC-V ISA Specifications
Shaderoo
OpenGL 4.5 Quick Reference Card

Result as of Hackweek 2024

WebGL turned out to be insufficient, it only supports OpenGL ES 3.0 but imageLoad/imageStore needs ES 3.1. So we switched directions and had to write a native C++ host for the shaders.

As of Hackweek Friday, the kernel attempts to boot and outputs messages, but panics due to missing memory regions.

Since then, some bugs were fixed and enough hardware emulation implemented, so that now Linux boots with framebuffer support and it's possible to log in and run programs!

The repo with a demo video is available at https://github.com/Vogtinator/risky-v

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SUSE Prague claw machine by anstalker

Project Description

The idea is to build a claw machine similar to e.g. this one:

Why? Well, it could be a lot of fun!

But also it's a great way to dispense SUSE and openSUSE merch like little Geekos at events like conferences, career fairs and open house events.

Goal for this Hackweek

Build an arcade claw machine.

Resources

In French, an article about why you always lose in claw machine games:

We're looking for handy/crafty people in the Prague office:

• woodworking XP or equipment
• arduino/raspi embedded programming knowledge
• Anthony can find a budget for going to GM and buying servos and such ;)

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Framework laptop integration by nkrapp

Project Description

Although openSUSE does run on the Framework laptops out-of-the-box, there is still room to improve the experience. The ultimate goal is to get openSUSE on the list of community supported distros

Goal for this Hackweek

The goal this year is to at least package all of the soft- and firmware for accessories like the embedded controller, Framework 16 inputmodule and other tools. I already made some progress by packaging the inputmodule control software, but the firmware is still missing

Resources

As I only have a Framework laptop 16 and not a 13 I'm looking for people with hardware that can help me test

Progress:

Update 1:

The project lives under my home for now until I can get an independent project on OBS: Framework Laptop project

Also, the first package is already done, it's the cli for the led-matrix spacer module on the Framework Laptop 16. I am also testing this myself, but any feedback or questions are welcome.

You can test the package on the Framework 16 by adding this repo and installing the package inputmodule-control

Update 2:

I finished packaging the python cli/gui for the inputmodule. It is using a bit of a hack because one of the dependencies (PySimpleGUI) recently switched to a noncommercial license so I cannot ship it. But now you can actually play the games on the led-matrix (the rust package doesn't include controls for the games). I'm also working on the Framework system tools now, which should be more interesting for Framework 13 users.

You can test the package on the Framework 16 by installing python311-framework16_inputmodule and then running "ledmatrixctl" from the command line.

Update 3:

I packaged the framework_tool, a general application for interacting with the system. You can find it some detailed information what it can do here. On my system everything related to the embedded controller functionality doesn't work though, so some help testing and debugging would be appreciated.

Update 4:

Today I finished the qmk interface, which gives you a cli (and gui) to configure your Framework 16 keyboard. Sadly the Python gui is broken upstream, but I added the qmk_hid package with the cli and from my testing it works well.

Final Update:

All the interesting programs are now done, I decided to exclude the firmware for now since upstream also recommends using fwupd to update it. I will hack on more things related to the Framework Laptops in the future so if there are any ideas to improve the experience (or any bugs to report) feel free to message me about it.

As a final summary/help for everyone using a Framework Laptop who wants to use this software:

The source code for all packages can be found in repositories in the Framework organization on Github

All software can be installed from this repo (Tumbleweed)

The available packages are:

• framework-inputmodule-control (FW16) - play with the inputmodules on your Framework 16 (b1-display, led-matrix, c1-minimal)

• python-framework16_inputmodule (FW16) - same as inputmodule-control but is needed if you want to play and crontrol the built-in games in the led-matrix (call with ledmatrixctl or ledmatrixgui)

• framework_tool (FW13 and FW 16) - use to see and configure general things on your framework system. Commands using the embedded controller might not work, it looks like there are some problems with the kernel module used by the EC. Fixing this is out of scope for this hackweek but I am working on it

• qmk_hid (FW16) - a cli to configure the FW16 qmk keyboard. Sadly the gui for this is broken upstream so only the cli is usable for now

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Capyboard, ESP32 Development Board for Education by emiler

Description

Capyboard is an ESP32 development board built to accept individual custom-made modules. The board is created primarily for use in education, where you want to focus on embedded programming instead of spending time with connecting cables and parts on a breadboard, as you would with Arduino and other such devices. The board is not limited only to education and it can be used to build, for instance, a very powerful internal meteo-station and so on.

I already have one initial prototype ready and tested. The next iteration addresses several issues the first prototype had. I am planning on finishing up the mainboard and one of the modules this week.

This project is also a part of my master's thesis.

Goals

• Finish testing of a new prototype
• Publish source files
• Documentation completion
• Finish writing thesis

Resources

• github.com/realcharmer/capyboard
• github.com/realcharmer/capyboard-starter
• github.com/realcharmer/capyboard-docs
• docs.capyboard.dev

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Build a split keyboard from scratch by mpagot

Description

I'm getting older... this summer I experienced an annoying and persistent tingling in one hand and arm. That was the initial motivation to get more interested in ergonomic work gadgets, and from that to split keyboards. And that was the entrance in a rabbit hole.

Which keyboard I like to create:

• Split keyboard for ergonomic (I'm not primary interested in having it portable)
• I have big hands: I like it to fit as much as possible my hands measures
• Columnar stagger keys position
• Not too few keys (at the moment I'm at 24 + 24)
• One row thumb cluster
• No wireless, not to have batteries and for security reason
• CherryMX, or generally speaking no low profile/corne choc
• Hot swap Socket switches

Goals

• Create PCB design for a split keyboard
• Get it produced
• Mount it
• Evaluate FWs

Resources

• Main project repo: Zenga
• ZKM config for a hand wired 4 keys something: nne
• Blog posts opensuse.hackweek.2024

Progress

Day1

Get the existing Ergogen project working on my TW machine Get Kicad as flatpack Go back to the https://flatfootfox.com/ergogen-part3-pcbs/ Join the #ergogen Discord channel and ask for help about the nets

Day2

Redesign the keyboard matrix on Inkscape Implement it in the Ergogen YAML format Create a Kicad PCB file Start routing it Iterate over the matrix arrangement to try to implement it like 2 layer board and ideally with not vias Get some Kicad tutorials

Day3

Get my hand dirty building a 2x2 key matrix --> welcome to nne Look at ZKM and how to configure it --> https://github.com/michelepagot/zmk-config-nne Get the FW built by github, try to flash it: get matrix scan pulse but no keys to the PC Get in contact with ceoloide, an Ergogen maintainer, about net issue.

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