Project Description
Currently kernel module signature be attached in the end of kernel module (ko file). Scott Bahling has raised that there have some benefits that kernel allows to load module with a separate signature file.
Current module signature is PKCS#7 format, I thought that it's not hard to do that. But we will need a new system call for this.
Goal for this Hackweek
Implement a proof of concept in hackweek 20.
Resources
Base on the latest kernel mainline.
No Hackers yet
Looking for hackers with the skills:
This project is part of:
Hack Week 20
Comments
Similar Projects
early stage kdump support by mbrugger
Project Description
When we experience a early boot crash, we are not able to analyze the kernel dump, as user-space wasn't able to load the crash system. The idea is to make the crash system compiled into the host kernel (think of initramfs) so that we can create a kernel dump really early in the boot process.
Goal for the Hackweeks
- Investigate if this is possible and the implications it would have (done in HW21)
- Hack up a PoC (done in HW22 and HW23)
- Prepare RFC series (giving it's only one week, we are entering wishful thinking territory here).
update HW23
- I was able to include the crash kernel into the kernel Image.
- I'll need to find a way to load that from
init/main.c:start_kernel()
probably afterkcsan_init()
- I workaround for a smoke test was to hack
kexec_file_load()
systemcall which has two problems:- My initramfs in the porduction kernel does not have a new enough kexec version, that's not a blocker but where the week ended
- As the crash kernel is part of init.data it will be already stale once I can call
kexec_file_load()
from user-space.
The solution is probably to rewrite the POC so that the invocation can be done from init.text (that's my theory) but I'm not sure if I can reuse the kexec infrastructure in the kernel from there, which I rely on heavily.
update HW24
- Day1
- rebased on v6.12 with no problems others then me breaking the config
- setting up a new compilation and qemu/virtme env
- getting desperate as nothing works that used to work
- Day 2
- getting to call the invocation of loading the early kernel from
__init
afterkcsan_init()
- getting to call the invocation of loading the early kernel from
Day 3
- fix problem of memdup not being able to alloc so much memory... use 64K page sizes for now
- code refactoring
- I'm now able to load the crash kernel
- When using virtme I can boot into the crash kernel, also it doesn't boot completely (major milestone!), crash in
elfcorehdr_read_notes()
Day 4
- crash systems crashes (no pun intended) in
copy_old_mempage()
link; will need to understand elfcorehdr... - call path
vmcore_init() -> parse_crash_elf_headers() -> elfcorehdr_read() -> read_from_oldmem() -> copy_oldmem_page() -> copy_to_iter()
- crash systems crashes (no pun intended) in
Day 5
- hacking
arch/arm64/kernel/crash_dump.c:copy_old_mempage()
to see if crash system really starts. It does. - fun fact: retested with more reserved memory and with UEFI FW, host kernel crashes in init but directly starts the crash kernel, so it works (somehow) \o/
- hacking
TODOs
- fix elfcorehdr so that we actually can make use of all this...
- test where in the boot
__init()
chain we can/should callkexec_early_dump()
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
- Fix at least 2 security bugs
- 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
Linux on Cavium CN23XX cards by tsbogend
Before Cavium switched to ARM64 CPUs they developed quite powerful MIPS based SOCs. The current upstream Linux kernel already supports some Octeon SOCs, but not the latest versions. Goal of this Hack Week project is to use the latest Cavium SDK to update the Linux kernel code to let it running on CN23XX network cards.
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.
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