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When the 6.14 kernel is released later this month, it will include the usual set of internal changes that users should never notice, with the possible exception of changes that bring performance improvements. One of those changes is frozen pages, a memory-management optimization that should fly mostly under the radar. When Hannes Reinecke reported a crash in 6.14, though, frozen pages suddenly came into view. There is a workaround for this problem, but it seems there is a fair amount of work to be done that nobody had counted on to solve the problem properly.

Greg Kroah-Hartman has announced the release of the 6.13.7, 6.12.19, 6.6.83, 6.1.131, 5.15.179, 5.10.235, and 5.4.291 stable kernels. They all contain a relatively large number of important fixes throughout the kernel tree.

Security updates have been issued by Debian (chromium), Fedora (ffmpeg, qt6-qtwebengine, tigervnc, and xorg-x11-server-Xwayland), Red Hat (fence-agents and libxml2), SUSE (amazon-ssm-agent, ark, chromium, fake-gcs-server, gerbera, google-guest-agent, google-osconfig-agent, grafana, kernel, libtinyxml2-10, podman, python311, python312, restic, ruby3.4-rubygem-rack, and thunderbird), and Ubuntu (jinja2, linux-azure, linux-azure-4.15, linux-lts-xenial, linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency, netatalk, python3.5, python3.8, rar, unrar-nonfree, and xorg-server, xwayland).

Inside this week's LWN.net Weekly Edition:

• Front: PyPI terms of service; Zig 0.14; Matrix; Timer IDs and ABI; Module integrity checking; Capability analysis.
• Briefs: Path traversal; Below vulnerability; Ubuntu 25.04; Flang; Gstreamer 1.26.0; Framework Mono 6.14.0; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

On February 25, the Python Software Foundation (PSF), which runs the Python Package Index (PyPI), announced new terms of service (ToS) for the repository. That has led to some questions about the new ToS, and the process of coming up with them. For one thing, the previous terms of use for the service were shorter and simpler, but there are other concerns with specific wording in the new agreement.

Damien Neil has written an article for the Go Blog about path traversal vulnerabilities and the os.Root API added in Go 1.24 to help prevent them.

Root permits relative path components and symlinks that do not escape the root. For example, root.Open("a/../b") is permitted. Filenames are resolved using the semantics of the local platform: On Unix systems, this will follow any symlink in "a" (so long as that link does not escape the root); while on Windows systems this will open "b" (even if "a" does not exist).

The Zig project has announced the release of the 0.14 version of the language, including changes from more than 250 contributors. Zig is a low-level, memory-unsafe programming language that aims to compete with C instead of depending on it. Even though the language has not yet had a stable release, there are a number of projects using it as an alternative to C with better metaprogramming. While the project's release schedule has been a bit inconsistent, with the release of version 0.14 being delayed several times, the release contains a number of new convenience features, broader architecture support, and the next steps toward removing Zig's dependency on LLVM.

The SUSE Security Team blog has a post with a detailed analysis of a vulnerability (CVE-2025-27591) in the below tool for recording and displaying system data.

In January 2025, Below was packaged and submitted to openSUSE Tumbleweed. Below runs as a systemd service with root privileges. The SUSE security team monitors additions and changes to systemd service unit files in openSUSE Tumbleweed, and through this we noticed problematic log directory permissions applied in Below's code.

The LLVM project's Fortran compiler, which has for many years gone by the name "flang-new", will now simply be "flang", starting from LLVM's 20.1.0 release on March 4. The announcement, which includes details about the history of flang, comes after a long period of development and discussion. The community has considered renaming flang several times before now, but has always held off out of a feeling that the compiler was not yet ready. Now, the members of the project believe that flang has become stable and complete enough to earn its name.

We are almost 10 years from the first announcement of what would become LLVM Flang. In the LLVM monorepo alone there have been close to 10,000 commits from around 400 different contributors. Undoubtedly more in Classic Flang before that.

Version 1.26.0 of the GStreamer cross-platform multimedia framework has been released. Notable changes in this release include support for the H.266 Versatile Video Coding (VVC) codec, Low Complexity Enhancement Video Coding (LCEVC) support, closed caption improvements, and JPEG XS image codec support.

Security updates have been issued by Debian (libmodbus), Fedora (thunderbird and vyper), Mageia (firefox, nss, python-django, python-jinja2, and thunderbird, thunderbird-l10n), Oracle (bind, kernel, rsync, and tigervnc), Red Hat (.NET 8.0, .NET 9.0, and libxml2), SUSE (iniparser and kernel), and Ubuntu (dotnet8, dotnet9, freerdp2, jinja2, libreoffice, linux, linux-hwe, linux-aws, linux-aws-hwe, linux-gcp, linux-gcp-4.15, linux-kvm, linux-oracle, linux-kvm, and opensc).

Matrix provides an open network for secure, decentralized communication. It has enjoyed some success over the last few years as an IRC replacement and real-time chat for a number of open-source projects. But adoption by a subset of open-source developers is a far cry from the mainstream adoption that Matthew Hodgson, Matrix project lead and CEO of Element (the company that created Matrix), would like to see. At FOSDEM 2025, he discussed the history of Matrix, its missteps in chasing mainstream adoption, its current status, as well as some of the wishlist features for taking Matrix into the mainstream.

Version 6.14.0 of Framework Mono has been announced.

This is the first release of Framework Mono from its new home at WineHQ. It includes work from the past 5 years that was never included in a stable release because no stable branch had been created in that time. Highlights are native support for ARM64 on macOS and many improvements to windows forms for X11.

See the release notes for a full list of new features and plans for future releases.

Security updates have been issued by Debian (libaws, ruby2.7, and squid), Fedora (bigloo, emacs, neovim, python-jinja2, rizin, and tree-sitter), Oracle (kernel), Red Hat (grub2, kernel, kernel-rt, and libxml2), SUSE (iniparser, kernel, krb5, libxkbfile, and u-boot), and Ubuntu (gnuchess, openjdk-17-crac, openjdk-21-crac, and openvpn).

The Python project's recent switch to a tail-calling interpreter may not provide as large a speed advantage as initially thought. A blog post from Nelson Elhage gives the details. In short, switching to a tail-call-based interpreter accidentally works around an unfixed regression in LLVM 19. On other compilers, the performance benefit (while still present) is more moderate.

When the tail-call interpreter was announced, I was surprised and impressed by the performance improvements, but also confused: I'm not an expert, but I'm passingly-familiar with modern CPU hardware, compilers, and interpreter design, and I couldn't explain why this change would be so effective. I became curious – and perhaps slightly obsessed – and the reports in this post are the result of a few weeks of off-and-on compiling and benchmarking and disassembly of dozens of different Python binaries, in an attempt to understand what I was seeing.

One of the advantages of the Rust type system is its ability to encapsulate requirements about the state of the program in the type system; often, this state includes which locks must be held to be able to carry out specific operations. C lacks the ability to express these requirements, but there would be obvious benefits if that kind of feature could be grafted onto the language. The Clang compiler has made some strides in that direction with its thread-safety analysis feature; two developers have been independently working to take advantage of that work for the kernel.

Security updates have been issued by Debian (openvpn and thunderbird), Fedora (buildah, chromium, podman-tui, python-spotipy, qt6-qtwebengine, and vim), Mageia (chromium-browser-stable and gpac), Oracle (krb5), Red Hat (firefox, kernel, kernel-rt, libxml2, and pcs), SUSE (buildah, chromedriver, chromium, firefox, go1.23, go1.24, grype, python, python311-GitPython, ruby3.4-rubygem-rack, thunderbird, and xen), and Ubuntu (xorg-server, xorg-server-hwe-16.04, xorg-server-hwe-18.04).

Linus has released 6.14-rc6 for testing. "This release remains on track, nothing special to report".

The 6.6.82 stable kernel has been released. "All i386 users of the 6.6 kernel series must upgrade (as they skipped the last release.) All other arches can skip this one as it should not affect them."

Greg Kroah-Hartman has announced the release of four more stable kernels: 6.13.6, 6.12.18, 6.6.81, and 6.1.130. Unlike a normal release, Kroah-Hartman did not call for all users to update their kernels. Specifically, the 6.6.81 kernel is currently broken on i386 systems, and users should wait for 6.6.82.