Modernize ocfs2 by goldwynr

Ocfs2 has gone into a stage of neglect and disrepair. Modernize the code to generate enough interest.

Goals: * Change the mount sequence to use fscontext * Move from using bufferhead to bio/folios * Use iomap * Run it through xfstests

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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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Officially Become a Kernel Hacker! by m.crivellari

Description

My studies as well my spare time are dedicated to the Linux Kernel. Currently I'm focusing on interrupts on x86_64, but my interests are not restricted to one specific topic, for now.

I also "played" a little bit with kernel modules (ie lantern, a toy packet analyzer) and I've added a new syscall in order read from a task A, the memory of a task B.

Maybe this will be a good chance to...

Goals

• create my first kernel patch

Resources

• https://www.kernel.org/doc/html/latest/process/submitting-patches.html
• https://git-send-email.io/ (mentioned also in the kernel doc)
• https://javiercarrascocruz.github.io/kernel-contributor-1

Achivements

• found while working on a bug, this is the 1st patch: cifs: avoid deadlocks while updating iface [✅ has been merged]

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ESETv2 Emulator / interpreter by m.crivellari

Description

ESETv2 is an intriguing challenge developed by ESET, available on their website under the "Challenge" menu. The challenge involves an "assembly-like" language and a Python compiler that generates .evm binary files.

This is an example using one of their samples (it prints N Fibonacci numbers):

.dataSize 0
.code

loadConst 0, r1 # first
loadConst 1, r2 # second

loadConst 1, r14 # loop helper

consoleRead r3

loop:
    jumpEqual end, r3, r15

    add r1, r2, r4
    mov r2, r1
    mov r4, r2

    consoleWrite r1

    sub r3, r14, r3
    jump loop
end:
hlt

This language also supports multi-threading. It includes instructions such as createThread to start a new thread, joinThread to wait until a thread completes, and lock/unlock to facilitate synchronization between threads.

Goals

• create a full interpreter able to run all the available samples provided by ESET.
• improve / optimize memory (eg. using bitfields where needed as well as avoid unnecessary memory allocations)

Resources

• Challenge URL: https://join.eset.com/en/challenges/core-software-engineer
• My github project: https://github.com/DispatchCode/eset_vm2 (not 100% complete)

Achivements

Project still not complete. Added lock / unlock instruction implementation but further debug is needed; there is a bug somewhere. Actually the code it works for almost all the examples in the samples folder. 1 of them is not yet runnable (due to a missing "write" opcode implementation), another will cause the bug to show up; still not investigated, anyhow.

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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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Add a machine-readable output to dmidecode by jdelvare

Description

There have been repeated requests for a machine-friendly dmidecode output over the last decade. During Hack Week 19, 5 years ago, I prepared the code to support alternative output formats, but didn't have the time to go further. Last year, Jiri Hnidek from Red Hat Linux posted a proof-of-concept implementation to add JSON output support. This is a fairly large pull request which needs to be carefully reviewed and tested.

Goals

Review Jiri's work and provide constructive feedback. Merge the code if acceptable. Evaluate the costs and benefits of using a library such as json-c.

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FastFileCheck work by pstivanin

Description

FastFileCheck is a high-performance, multithreaded file integrity checker for Linux. Designed for speed and efficiency, it utilizes parallel processing and a lightweight database to quickly hash and verify large volumes of files, ensuring their integrity over time.

https://github.com/paolostivanin/FastFileCheck

Goals

• Release v1.0.0

Design overwiew:

• Main thread (producer): traverses directories and feeds the queue (one thread is more than enough for most use cases)
• Dedicated consumer thread: manages queue and distributes work to threadpool
• Worker threads: compute hashes in parallel

This separation of concerns is efficient because:

• Directory traversal is I/O bound and works well in a single thread
• Queue management is centralized, preventing race conditions
• Hash computation is CPU-intensive and properly parallelized

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