Linux Weekly News
Security updates for Thursday
[$] LWN.net Weekly Edition for December 25, 2025
- Front: 2025 retrospective; Dirk and Linus talk; successful open-source documentation projects; verifier-state pruning in BPF; Linux 32-bit timeline; BPF state visualizer; systemd v259.
- Briefs: linux-next maintainer; 2025 TAB; Git in Debian; Elementary OS 8.1; Qubes OS 4.3.0; GDB 17.1; Incus 6.20; systemd v259; Quotes; ...
- Announcements: Newsletters, conferences, security updates, patches, and more.
[$] A 2025 retrospective
[$] What's new in systemd v259
The systemd v259 release was announced on December 17, just three months after v258. It is a more modest release but still includes a number of important changes such as a new option for the run0 command (an alternative to sudo), ability to mount user home directories from the host in virtual machines, as well as under-the-hood changes with dlopen() for library linking, the ability to compile systemd with musl libc, and more.
Security updates for Wednesday
Elementary OS 8.1 released
Version 8.1 of elementary OS has been released. Notable changes in this release include making the Wayland session the default, changes to window management and multitasking, as well as a number of accessibility improvements. The 8.1 release is the first to be made available for Arm64 devices, which should allow users to run elementary on Apple M-series hardware or other Arm devices that can load UEFI-supporting firmware, such as some Raspberry Pi models. See the blog post for a full list of changes.
[$] A high-memory elimination timeline for the kernel
[$] Verifier-state pruning in BPF
The BPF verifier works, on a theoretical level, by considering every possible path that a BPF program could take. As a practical matter, however, it needs to do that in a reasonable amount of time. At the 2025 Linux Plumbers Conference, Mahé Tardy and Paul Chaignon gave a detailed explanation (slides; video) of the main mechanism that it uses to accomplish that: state pruning. They focused on two optimizations that help reduce the number of paths the verifier needs to check, and discussed some of the complications the optimizations introduced to the verifier's code.
Security updates for Tuesday
Incus 6.20 released
Version 6.20 of the Incus container and virtual-machine management system has been released. Notable changes in this release include a new standalone command to add IncusOS servers to a cluster, qcow2-formatted volumes for clustered LVM, and reverse DNS records in OVN. See the announcement for a full list of changes.
GDB 17.1 released
Qubes OS 4.3.0 released
Jackson: Debian’s git transition
Everyone who interacts with Debian source code should be able to do so entirely in git.
That means, more specifically:
- All examination and edits to the source should be performed via normal git operations.
- Source code should be transferred and exchanged as git data, not tarballs. git should be the canonical form everywhere.
- Upstream git histories should be re-published, traceably, as part of formal git releases published by Debian.
- No-one should have to learn about Debian Source Packages, which are bizarre, and have been obsoleted by modern version control.
This is very ambitious, but we have come a long way!
[$] Tools for successful documentation projects
Loong64 is now an official Debian architecture
Security updates for Monday
Kernel prepatch 6.19-rc2
Results from the 2025 TAB election
FreeBSD laptop progress
The FreeBSD Foundation has a blog post about the progress it has made in 2025 on the Laptop Support & Usability Project for FreeBSD. The foundation committed $750,000 to the project in 2025 and has made progress on graphics drivers, Wi-Fi 4 and 5 support, audio improvements, sleep states, and more.
The installer for FreeBSD has gained a couple of new features that benefit laptop users. In 15.0 the installer now supports downloading and installing firmware packages after the FreeBSD base system installation is complete. Coming in 15.1 it will be possible to install the KDE graphical desktop environment during the installation process. Grateful thanks to Bjoern Zeeb and Alfonso Siciliano respectively. [...]
The project continues into 2026 with a similar sized investment and scope. Key targets include completing work on sleep states (modern standby and hibernate), adding support for graphics drivers up to Linux 6.18, Wi-Fi 6 support, USB4 and Thunderbolt support, HDMI improvements, UVC webcam support, and Bluetooth improvements.
A substantial testing program will also start in January, aiming to test all the functionality together across a range of hardware. Community testers are very welcome to help out, the Foundation will release a blog post and send an invite to help to the Desktop mailing list some time in January 2026.
[$] A visualizer for BPF program state
The BPF verifier is complicated. It needs to check every possible path that a BPF program's execution could take. The fact that its determination of whether a BPF program is safe is based on the whole lifetime of the program, instead of simple local factors, means that the cause of a verification failure is not always obvious. Ihor Solodrai and Jordan Rome gave a presentation (slides) at the 2025 Linux Plumbers Conference in Tokyo about the BPF verifier visualizer that they have been building to make diagnosing verification failures easier.