LWN.net

Three Saturday stable kernels
Greg Kroah-Hartman has announced the release of the 6.13.8, 6.12.20, and 6.6.84 stable kernels. Each contains a number of important fixes throughout the kernel tree; users of those series should upgrade.
[$] OSI election ends with unsatisfying results
The Open Source Initiative (OSI) has announced the results of its recent board of directors election. Ruth Suehle and McCoy Smith are new to the board, while Carlo Piana will serve another term. The results, however, seem tainted in the eyes of some participants and observers. The election has been plagued by missteps from the beginning. It has culminated with the exclusion of three candidates for failing to meet a requirement to sign the OSI board agreement, which was added after the election was over and before results were tallied or announced.
[$] The guaranteed contiguous memory allocator
Julien Malka proposes method for detecting XZ-like backdoors
Julien Malka has called for the NixOS project to use build-reproducibility to detect when a program has a maintainer-generated tarball that results in a different artifact than building from source. There are good reasons for projects to release maintainer-generated tarballs, but since the materials included in them are usually documentation, extra build scripts, and so on, it makes sense to check that they don't influence the final build output. While this would not have stopped last year's XZ backdoor, it would have made it harder to hide.
People are often convinced that OSS is more trustworthy than closed-source software because the code can be audited by practitioners and security professionals in order to detect vulnerabilities or backdoors. In this instance, this procedure has been made difficult by the fact that part of the code activating the backdoor was not included in the sources available within the git repository but was instead present in the maintainer-provided tarball. While this was used to hide the backdoor out of sight of most investigating eyes, this is also an opportunity for us to improve our software supply chain security processes.[$] Multiple memory classes for address-space isolation
Brendan Jackman has been working to try to get ahead of the next hardware CPU vulnerability before it gets discovered. In January, he posted the second version of a patch set that introduces address-space isolation (ASI) as a way of preventing future CPU vulnerabilities from leaking important information. The core concept is to ensure that data that is not currently needed is not present in memory, so that speculative execution cannot leak it. The work is nowhere near ready to be incorporated into the mainline kernel — not least of all because it has a large performance impact in its current form — but it is likely to once again be a topic of discussion at the 2025 Linux Filesystem, Memory Management, and BPF Summit.
Introducing rpi-image-gen for customized Raspberry Pi images
Raspberry Pi has announced rpi-image-gen, a tool to create custom software images for its devices.
rpi-image-gen is a Bash orientated scripting engine capable of producing software images with different on-disk partition layouts, file systems and profiles using collections of metadata and a defined flow of execution. It provides the means to create a highly customised software image for your Raspberry Pi device. rpi-image-gen is human readable, auditable and easy to use.The Git repository for rpi-image-gen has a number of examples to help users get started making their own custom images.
An Asahi Linux 6.14 progress report
Now that Rust for Linux abstractions are starting to be merged at a healthy pace, we are faced with an emerging challenge. It is rare for any kernel patch to survive the mailing list without at least a couple of non-trivial changes, and Rust abstractions are no exception. Every time an abstraction used by our driver is merged, we must drop our downstream version and rebase the driver atop the version accepted upstream. This is grueling, menial, and unpleasant work, and Janne has our deepest gratitude for volunteering his time to get through it.
Security updates for Friday
[$] MM medley: huge page allocation, page promotion, KSM, and BPF
[$] MM medley: huge page allocation, page promotion, KSM, and BPF
Security updates for Thursday
Security updates for Thursday
[$] LWN.net Weekly Edition for March 20, 2025
- Front: Oxidizr; Spectre mitigations; Frozen pages; Mapcount madness; Open-source risks; /e/OS.
- Briefs: Supply chain attacks; SystemRescue 12.00; Casual Make; GIMP 3.0; Git 2.49.0; GNOME 48; PeerTube 7.1; Quotes; ...
- Announcements: Newsletters, conferences, security updates, patches, and more.
GNOME 48 released
GNOME 48 ("Bengaluru") has been released. As usual, this release includes a number of new features and enhancements including support for shortcuts in the Orca screen reader on Wayland, new fonts, addition of image editing to Image Viewer, and more.
GNOME 48 includes a number of notable performance improvements. The most significant of these is the introduction of dynamic triple buffering. This change has undergone significant review and testing over a period of five years and improves the perceived smoothness of changes on screen, with fewer skipped frames and more fluid animations. This has been achieved by enhancing the concurrency capabilities of Mutter, the GNOME display manager, and is particularly effective at handling sudden bursts of activity.The GNOME 48 release also adds new applications to the GNOME Circle collection, such as Drum Machine and the Iotas note-taking application. See "What's new for developers" a rundown of improvements for developers in GNOME 48.
GNOME 48 released
GNOME 48 ("Bengaluru") has been released. As usual, this release includes a number of new features and enhancements including support for shortcuts in the Orca screen reader on Wayland, new fonts, addition of image editing to Image Viewer, and more.
GNOME 48 includes a number of notable performance improvements. The most significant of these is the introduction of dynamic triple buffering. This change has undergone significant review and testing over a period of five years and improves the perceived smoothness of changes on screen, with fewer skipped frames and more fluid animations. This has been achieved by enhancing the concurrency capabilities of Mutter, the GNOME display manager, and is particularly effective at handling sudden bursts of activity.The GNOME 48 release also adds new applications to the GNOME Circle collection, such as Drum Machine and the Iotas note-taking application. See "What's new for developers" a rundown of improvements for developers in GNOME 48.
[$] Better CPU vulnerability mitigation configuration
Modern CPUs all have multiple hardware vulnerabilities that the kernel needs to mitigate; the 6.13 kernel has workarounds for 14 security-sensitive CPU bugs just on x86_64. Several of those have multiple variants, or multiple mitigations that apply on different microarchitectures. There are different kernel command-line options for each of these mitigations, which leads to a confusing situation for users trying to figure out how to configure their systems. David Kaplan recently posted a patch set that adds a single, unified command-line option for controlling mitigations and simplifies the logic for detecting, configuring, and applying them as well. If it is merged, the patch set could make it much easier for users to navigate the complicated web of CPU vulnerabilities and their mitigations.
PeerTube 7.1 released
Version 7.1 of PeerTube, a tool for sharing videos online, has been released. Notable features in this release include improved support for the Podcast 2.0 standard, better playback stability, and a new view protocol enabled by default to allow PeerTube to handle more simultaneous viewers. See the release notes for more details.
[$] A look at /e/OS on tablet hardware
/e/OS is a privacy-centric, open-source mobile operating system that has primarily been targeted at mobile phones, with only a few community supported images available for tablet devices. In December, Murena—a company that sells devices with /e/OS preinstalled—announced that /e/OS now officially supports tablets as well, starting with the Pixel tablet. The user experience is close enough to mainstream alternatives to make it attractive, but there are some under-the-hood problems that may give users pause.
Supply Chain Attacks on Linux distributions (Fenrisk)
We successfully identified vulnerabilities in the Pagure, the Git forge used by Fedora to store their package definitions. We also compromised Open Build Service, the all-in-one toolchain used and developed by the openSUSE project for compilation and packaging.
Their exploitation by malicious actors would have led to the compromise of all the packages of the distributions Fedora and openSUSE, as well as their downstream distributions, impacting millions of Linux servers and desktops.
[Update: SUSE has put out a statement about the vulnerability; "While this is a serious vulnerability that needed to be fixed quickly, the impact was inaccurately described."]