Vue lecture
PC Gamer on the scx_horoscope scheduler
The scheduler is full of bizarre features, like its ability to perform real planetary calculations based on accurate geocentric planetary positions, lunar phase scheduling (the full moon gives a 1.4x boost to tasking, apparently) and "zodiac-based task classification".That latter feature is easily one of my favourite bits. Specific planetary bodies "rule" over specific system tasks, so the Sun is in charge of critical system processes, the Moon (tied to emotions, of course) rules over interactive tasks, and Jupiter is assigned to memory-heavy applications, among others.
[$] Who should vote in Fedora elections?
Creating fair governance models for open-source projects is not easy; defining criteria for participants to receive membership and voting rights is a particularly thorny problem for projects that have elections for representative bodies. The Fedora Council, the project's top-level governance body, is wrestling with that conundrum now. This was triggered by a Fedora special-interest group (SIG) granting temporary membership to at least one person for the sole purpose of allowing them to vote in the most recent Fedora Engineering Steering Council (FESCo) election. That opened a large can of worms about what it means to be a contributor and how contributors can be identified for voting purposes.
Security updates for Wednesday
A critical GnuPG security update
critical security bug" in recent GnuPG releases.
A crafted CMS (S/MIME) EnvelopedData message carrying an oversized wrapped session key can cause a stack buffer overflow in gpg-agent during the PKDECRYPT--kem=CMS handling. This can easily be used for a DoS but, worse, the memory corruption can very likley also be used to mount a remote code execution attack. The bug was introduced while changing an internal API to the FIPS required KEM API.
Only versions 2.5.13 through 2.5.16 are affected.
The GNU C Library is moving from Sourceware
While it was clear to the GNU Toolchain leadership that requirements were coming to improve the toolchain cyber-security posture, these requirements were not clear to all project developers. As part of receiving this feedback we have worked to document and define a secure development policy for glibc and at a higher level the GNU Toolchain. While Sourceware has started making some critical technical changes, the GNU Toolchain still faces serious, systemic concerns about securing a global, highly available service and building a sustainable, diverse sponsorship model.
This has been a long-running discussion; see this 2022 article for some background.
[$] Implicit arguments for BPF kfuncs
Xfwl4: the roadmap for a Xfce Wayland compositor
The Xfce team has announced that it will be providing funding to Brian Tarricone to work on xfwl4, a Wayland compositor for Xfce:
Xfwl4 will not be based on the existing xfwm4 code. Instead, it will be written from scratch in rust, using smithay building blocks.
The first attempt at creating an Xfce Wayland compositor involved modifying the existing xfwm4 code to support both X11 and Wayland in parallel. However, this approach turned out to be the wrong path forward for several reasons:
- Xfwm4 is architected in a way that makes it very difficult to put the window management behavior behind generic interfaces that don't include X11 specifics.
- Refactoring Xfwm4 is risky, since it might introduce new bugs to X11. Having two parallel code bases will allow for rapid development and experimentation with the Wayland compositor, with zero risk to break xfwm4.
- Some X11 window management concepts just aren't available or supported by Wayland protocols at this time, and dealing with those differences can be difficult in an X11-first code base.
- Using the existing codebase would require us to use C and wlroots, even if a better alternative is available.
Work has already commenced on the project, and the project hopes to share a development release in mid-2026.
Security updates for Tuesday
[$] Fedora and GPG 2.5
The GNU Privacy Guard (GPG) project decided to break from the OpenPGP standard for email encryption in 2023, and instead adopted its own homegrown LibrePGP specification. The GPG 2.4 branch, the last one to adhere to OpenPGP, will be reaching the end of life in mid-2026. The Fedora project is currently having a discussion about how that affects the distribution, its users, and what to offer once 2.4 is no longer receiving updates.
Stenberg: The end of the curl bug-bounty program
Curl creator Daniel Stenberg has written a blog post explaining why the project is ending its bug-bounty program, which started in April 2019:
The never-ending slop submissions take a serious mental toll to manage and sometimes also a long time to debunk. Time and energy that is completely wasted while also hampering our will to live.
I have also started to get the feeling that a lot of the security reporters submit reports with a bad faith attitude. These "helpers" try too hard to twist whatever they find into something horribly bad and a critical vulnerability, but they rarely actively contribute to actually improve curl. They can go to extreme efforts to argue and insist on their specific current finding, but not to write a fix or work with the team on improving curl long-term etc. I don't think we need more of that.
There are these three bad trends combined that makes us take this step: the mind-numbing AI slop, humans doing worse than ever and the apparent will to poke holes rather than to help.
Stenberg writes that he still expects "the best and our most
valued security reporters
" to continue informing the project when
security vulnerabilities are discovered. The program will officially
end on January 31, 2026.
Security updates for Monday
Kernel prepatch 6.19-rc7
So normally this would be the last rc of the release, but as I've mentioned every rc (because I really want people to be aware and be able to plan for things) this release we'll have an rc8 due to the holiday season.And while some of the early rc's were smaller than usual and it didn't seem necessary, right now I'm quite happy I made that call. Not because there's anything particularly scary here - the release seems to be going fairly smoothly - but because this rc7 really is larger than things normally are and should be at this point.
Along with the usual fixes, this -rc also includes a new document describing the process to replace the kernel project leadership should that become necessary in the absence of an arranged transition. The plan largely follows what was decided at the Maintainers Summit in December.
GNU C Library 2.43 released
[$] Filesystem medley: EROFS, NTFS, and XFS
GNU Guix 1.5.0 released
Version 1.5.0 of the GNU Guix package manager and the Guix System have been released. Notable improvements include the ability to run the Guix daemon without root privileges, support for 64-bit RISC-V, and experimental support for the GNU Hurd kernel.
The release comes with ISO-9660 installation images, virtual machine images, and with tarballs to install the package manager on top of your GNU/Linux distro, either from source or from binaries—check out the download page. Guix users can update by running guix pull.
It's been 3 years since the previous release. That's a lot of time, reflecting both the fact that, as a rolling release, users continuously get new features and update by running guix pull; but it also shows a lack of processes, something that we had to address before another release could be made.
During that time, Guix received about 71,338 commits by 744 people, which include many new features.
LWN last looked at Guix in February 2024.
Security updates for Friday
[$] Linux Kernel Runtime Guard reaches its 1.0 release
The Linux Kernel Runtime Guard (LKRG) is a out-of-tree loadable kernel module that attempts to detect and report violations of the kernel's internal invariants, such as might be caused by an in-progress security exploit or a rootkit. LKRG has been experimental since its initial release in 2018. In September 2025, the project announced the 1.0 version. With the promises of stability that version brings, users might want more information to decide whether to include it in their kernel.
30 years of ReactOS
ReactOS, an open-source project to develop an operating system that is compatible with Microsoft Windows NT applications and drivers, is celebrating 30 years since the first commit to its source tree. In that time there have been more than 88,000 commits from 301 contributors, for a total of 14,929,578 lines of code. There is, of course, much left to do.
It's been such a long journey that many of our contributors today, including myself, were not alive during this event. Yet our mission to deliver "your favorite Windows apps and drivers in an open-source environment you can trust" continues to bring people together. [...]
We're continuing to move ReactOS forward. Behind the scenes there are several out-of-tree projects in development. Some of these exciting projects include a new build environment for developers (RosBE), a new NTFS driver, a new ATA driver, multi-processor (SMP) support, support for class 3 UEFI systems, kernel and usermode address space layout randomization (ASLR), and support for modern GPU drivers built on WDDM.