Linux Weekly News

A few years ago, the only way to compile Rust code was using the rustc compiler with LLVM as a backend. Since then, several projects, including Mutabah's Rust Compiler (mrustc), GCC's Rust support (gccrs), rust_codegen_gcc, and Cranelift have made enormous progress on diversifying Rust's compiler implementations. The most recent such project, Eurydice, has a more ambitious goal: converting Rust code to clean C code. This is especially useful in high-assurance software, where existing verification and compliance tools expect C. Until such tools can be updated to work with Rust, Eurydice could provide a smoother transition for these projects, as well as a stepping-stone for environments that have a C compiler but no working Rust compiler. Eurydice has been used to compile some post-quantum-cryptography routines from Rust to C, for example.

Daniel Stenberg, the recipient of last year's Award for Excellence in Open Source from the European Open Source Academy, presented that award to this year's recipient: Greg Kroah-Hartman.

It's impossible to overstate the importance of the work Greg has done on Linux. In software, innovation grabs headlines, but stability saves lives and livelihoods. Every Android phone, every web server, every critical system running Linux depends on Greg's meticulous work. He ensures that when hospitals, banks, governments, and individuals rely on Linux, it doesn't fail them. His work represents the highest form of service: unglamorous, relentless, and essential.

The 6.18.8, 6.12.68, and 6.6.122 stable kernel updates have been released; each contains another set of important fixes.

Security updates have been issued by AlmaLinux (curl, gimp:2.8, glibc, grafana, grafana-pcp, kernel, osbuild-composer, php:8.3, python-urllib3, python3.11, and python3.12), Debian (chromium), Mageia (ceph, gpsd, libxml2, openjdk, openssl, and xen), SUSE (abseil-cpp, assertj-core, coredns, freerdp, java-11-openjdk, java-25-openjdk, libxml2, openssl-1_0_0, openssl-1_1, python, python-filelock, and python311-sse-starlette), and Ubuntu (kernel, linux, linux-aws, linux-aws-hwe, linux-hwe, linux-kvm, linux-oracle, linux, linux-aws, linux-kvm, linux-lts-xenial, linux-aws-fips, linux-fips, linux-fips, and texlive-bin).

Jeff Mahoney, who holds a vice-president position at SUSE, has posted a detailed proposal for improving the governance of the openSUSE project.

It's meant to be a way to move from governance by volume or persistence toward governance by legitimacy, transparency, and process - so that disagreements can be resolved fairly and the project can keep moving forward. Introducing structure and predictability means it easier for newcomers to the project to participate without needing to understand decades of accumulated history. It potentially could provide a clearer roadmap for developers to find a place to contribute.

The stated purpose is to start a discussion; this is openSUSE, so he is likely to succeed.

The extensible scheduler class (sched_ext) allows the installation of a custom CPU scheduler built as a set of BPF programs. Its merging for the 6.12 kernel release moved the kernel away from the "one scheduler fits all" approach that had been taken until then; now any system can have its own scheduler optimized for its workloads. Within any given machine, though, it's still "one scheduler fits all"; only one scheduler can be loaded for the system as a whole. The sched_ext sub-scheduler patch series from Tejun Heo aims to change that situation by allowing multiple CPU schedulers to run on a single system.

Security updates have been issued by AlmaLinux (java-25-openjdk, openssl, and python3.9), Debian (gimp, libmatio, pyasn1, and python-django), Fedora (perl-HarfBuzz-Shaper, python-tinycss2, and weasyprint), Mageia (glib2.0), Oracle (curl, fence-agents, gcc-toolset-15-binutils, glibc, grafana, java-1.8.0-openjdk, kernel, mariadb, osbuild-composer, perl, php:8.2, python-urllib3, python3.11, python3.11-urllib3, python3.12, and python3.12-urllib3), SUSE (alloy, avahi, bind, buildah, busybox, container-suseconnect, coredns, gdk-pixbuf, gimp, go1.24, go1.24-openssl, go1.25, helm, kernel, kubernetes, libheif, libpcap, libpng16, openjpeg2, openssl-1_0_0, openssl-1_1, openssl-3, php8, python-jaraco.context, python-marshmallow, python-pyasn1, python-urllib3, python-virtualenv, python311, python313, rabbitmq-server, xen, zli, and zot-registry), and Ubuntu (containerd, containerd-app and wlc).

Inside this week's LWN.net Weekly Edition:

• Front: PostmarketOS; LKRG 1.0; Fedora elections; EROFS, NTFS, and XFS; Fedora and GPG 2.5; BPF kfuncs.
• Briefs: curl bounties; GPG security; Guix 1.5.0; ReactOS turns 30; glibc 2.43; Rust 1.93; Xfwl4; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

We have received the sad news that Didier Spaier, maintainer of the blind-friendly Slackware-based Slint distribution, has recently passed away. Philippe Delavalade, who posted the announcement to the Slint mailing list, said:

Early 2015, I asked on the slackware list if brltty could be added in the installer; Didier answered promptly that he could do it on slint. Afterwards, he worked hard so that slint became as accessible as possible for visually impaired people.

You all know that all these years, he tried and succeeded to answer as quickly as possible to our issues and questions.

He will be irreplaceable.

The Open Source Initiative (OSI) has announced that it will not be holding the 2026 spring board election. Instead, it will be creating a working group to "review and improve OSI's board member selection process" and provide recommendations by September 2026:

The public election process was designed to gather community priorities and improve board member selection, while final appointments remained with the board.

Over time, that nuance has become a source of understandable confusion for community members. Many reasonably expected elections to function as elections normally do, and in fact, the board has generally adopted the electorate's recommendations. When a process feels unclear, trust suffers. When trust suffers, engagement becomes harder. This is especially problematic for an organization whose mission depends on legitimacy and credibility. [...]

OSI tried its experiment for the right reasons, but a variety of factors resulted in "elections" that are performatively democratic while being gameable and representative of only a small group, and we've learned from the results. Now we are making space to align our director selection process with our bylaws, to rebuild trust, and to develop better, more durable and truly representative participation in which the global stakeholder community can be heard.

LWN covered the previous OSI election in March 2025.

Phones running Linux are ubiquitous these days and it has been that way since Android started working toward dominance in the smartphone market. Unfortunately, Android has slowly increased its freedom-unfriendliness and has become something of a privacy nightmare. In a talk entitled "We need an open-source phone OS" at Open Source Summit Japan 2025, Luca Weiss described the smartphone landscape and gave an overview of postmarketOS as an alternative Linux operating system for mobile handsets.

PC Gamer has run an amusing review of the scx_horoscope scheduler for Linux, which uses astrology to optimize scheduling decisions.

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.

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 have been issued by AlmaLinux (java-1.8.0-openjdk), Debian (openssl), Fedora (assimp, chromium, curl, freerdp, gimp, and harfbuzz), Mageia (glibc, haproxy, iperf, and python-pyasn1), Red Hat (image-builder, openssl, and osbuild-composer), Slackware (mozilla), SUSE (avahi, cups, gio-branding-upstream, google-osconfig-agent, java-11-openjdk, java-17-openjdk, java-21-openjdk, kernel-firmware, libmatio-devel, libopenjp2-7, nodejs22, php8, python-python-multipart, python311-urllib3_1, qemu, and xen), and Ubuntu (ffmpeg, jaraco.context, openssl, and openssl, openssl1.0).

There is a new GnuPG update for a "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.

GNU C Library maintainer Carlos O'Donell has announced that the project will be moving its core services away from Sourceware in favor of services hosted at the Linux Foundation.

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.

The kernel's "kfunc" mechanism is a way of exporting kernel functions so that they can be called directly from BPF programs. There are over 300 kfuncs in current kernels, ranging in functionality from string processing (bpf_strnlen()) to custom schedulers (scx_bpf_kick_cpu()) and beyond. Sometimes these kfuncs need access to context information that is not directly available to BPF programs, and which thus cannot be passed in as arguments. The implicit arguments patch set from Ihor Solodrai is the latest attempt to solve this problem.

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 have been issued by AlmaLinux (kernel, kernel-rt, python-urllib3, python3.11-urllib3, and python3.12-urllib3), Debian (imagemagick, openjdk-11, openjdk-17, and openjdk-21), Fedora (bind, bind-dyndb-ldap, chromium, ghostscript, glibc, mingw-glib2, mingw-harfbuzz, mingw-libsoup, mingw-openexr, and qownnotes), Mageia (kernel-linus), Red Hat (osbuild-composer), SUSE (go1.24-openssl, go1.25-openssl, govulncheck-vulndb, kernel, nodejs22, openCryptoki, openvswitch3, python-pyasn1, python311, and qemu), and Ubuntu (git-lfs, node-form-data, and screen).

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.