lwn.net

Inside this week's LWN.net Weekly Edition:

• Front: OpenSUSE site age restrictions; Lots of LSFMM+BPF coverage; The tenth OpenPGP email summit.
• Briefs: Firefox 151.0; pgBackRest funding; RIP Peter G. Neumann; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

"Reclaim" is the task of finding memory that can be taken away from its current user and put to better uses within the system; it is a core part of the memory-management picture. The addition of the multi-generational LRU (MGLRU) was meant to provide a better reclaim implementation than the "traditional LRU" that preceded it, but MGLRU has complicated the situation instead. No fewer than three memory-management-track sessions at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit were focused on MGLRU, with an eye toward integrating it more fully, improving its performance, and addressing some problems encountered with Android systems.

Security updates have been issued by AlmaLinux (kernel, libpng, nginx, nginx:1.24, ruby, and ruby:3.3), Debian (gnutls28 and linux-6.1), Fedora (dnsmasq, kernel, keylime-agent-rust, perl-Net-CIDR-Lite, python-pysam, python-urllib3, rust-cargo-vendor-filterer, rust-ingredients, rust-oo7-cli, rust-rpki, rust-sevctl, and rust-tealdeer), Mageia (bind), Oracle (bind, giflib, gimp:2.8, kernel, libpng, rsync, ruby, and vim), Slackware (haveged and mozilla), SUSE (cockpit, dnsmasq, erlang26, freeipmi, git-bug, glibc, GraphicsMagick, haveged, ImageMagick, iproute2, kernel, openssh, perl-CryptX, perl-HTTP-Tiny, postgresql14, postgresql15, postgresql16, python-Pillow, rsync, tiff, and traefik), and Ubuntu (Highlight.js, linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-nvidia, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-oracle, linux-raspi, linux-realtime, linux, linux-aws, linux-aws-fips, linux-bluefield, linux-fips, linux-gcp, linux-gcp-5.4, linux-gcp-fips, linux-ibm, linux-ibm-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-xilinx-zynqmp, linux, linux-aws, linux-aws-fips, linux-fips, linux-gcp-4.15, linux-gcp-fips, linux-kvm, linux-oracle, linux, linux-aws, linux-aws-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-ibm-6.8, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-raspi, linux-raspi-realtime, linux-realtime, linux-realtime-6.8, linux, linux-aws, linux-hwe-6.17, linux-oem-6.17, linux-oracle, linux-raspi, linux-realtime, linux-realtime-6.17, and smarty3).

The OpenPGP Email Summit is an annual meeting for those who work on encrypted email and related topics. The tenth installment of this meeting took place in March 2026 and the minutes have now been published. As usual, a wide range of topics were discussed. Highlights included support for post-quantum cryptography (PQC) with multiple actors planning rollouts within this year, a promising new approach for making email signatures ubiquitous with the plan of making OpenPGP signed email a default, a new draft that brings reliable deletion (or "forward secrecy") features to OpenPGP, as well as a plan for transferring ownership of the OpenPGP.org domain.

Version 151.0 of the Firefox browser has been released. Significant changes include the ability to clear and restart a private-browsing session, better fingerprinting protection, control over the apparent location when using the Firefox VPN, and more.

Many people in the Linux community began using the operating system—and contributing to open source—at a tender age, often well before their 16th birthday. Thus, a recent change in openSUSE's terms of site (ToS) that required users of the project's web site to be "at least 16 years of age or the age of majority" in their jurisdiction has raised objections. The terms have since been modified, though users must still have parental approval to create accounts if they are younger than 16.

The kernel's this_cpu operations are meant to speed access to per-CPU variables. They are more optimal on some CPUs than others, though. During a memory-management-track session at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Yang Shi proposed a fundamental, and somewhat controversial, change to how these operations work in order to provide better performance on a wider range of architectures.

Compute Express Link (CXL) is a technology intended to enable the provision of "memory nodes" in data centers that provide (possibly shared) memory to nearby CPUs. It has, Dan Williams said at the beginning of his memory-management-track session on the topic at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, "been making memory-management problems worse since 2021". He used the session to provide an overview of the ways in which CXL can be expected to extend that record into the future.

There are many places in the kernel where performance can be improved by using per-CPU data. But, as it turns out, the kernel's allocator for per-CPU data has some performance problems of its own. Harry Yoo led a session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit to explore ways to address those problems and accelerate the allocation and initialization of per-CPU data.

Security updates have been issued by AlmaLinux (libpng and nginx), Debian (erlang, netatalk, and nginx), Fedora (mod_md and SDL2_image), Mageia (perl-libwww-perl, perl-HTTP-Message, perl-WWW-Mechanize-Cached, perl-File-XDG, perl-Path-Tiny, perl-YAML-Syck, postgresql15, and rclone), SUSE (agama, alloy, cacti, cloud-init, dnsmasq, emacs, firefox, glibc, go1.25, go1.26, google-cloud-sap-agent, google-guest-agent, ibus-rime, librime, imagemagick, kernel, libsndfile, nginx, ongres-scram, ongres-stringprep, plexus-testing,, openexr, openssh, PackageKit, perl-Text-CSV_XS, php-composer2, php8, postgresql16, postgresql18, python-lxml, python-python-multipart, python3, python311-urllib3, rmt-server, rsync, tiff, tree-sitter, util-linux, and xen), and Ubuntu (linux, linux-aws, linux-aws-5.4, linux-aws-fips, linux-azure, linux-azure-5.4, linux-azure-fips, linux-bluefield, linux-fips, linux-gcp, linux-gcp-5.4, linux-gcp-fips, linux-hwe-5.4, linux-ibm, linux-ibm-5.4, linux-iot, linux-kvm, linux-oracle, linux-oracle-5.4, linux-xilinx-zynqmp, linux, linux-aws, linux-kvm, linux-lts-xenial, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-raspi, and linux-xilinx-zynqmp).

In April, David Steele, maintainer of the popular pgBackRest backup and restore project for PostgreSQL, announced that he had archived the project and it would no longer be maintained due to lack of sponsorship. On May 18, he announced that a number of sponsors have stepped forward to ensure its continued development:

Over the last few weeks, a coalition of sponsors has come together to fund ongoing development. Their support means the project is no longer reliant on a single sponsor, giving pgBackRest the stability it needs for the long term.

[...] I'm looking forward to getting back to work. There are features and optimizations in the pipeline that I'm excited to share in upcoming releases. Thank you to our sponsors for making this possible, and thank you to the community for your patience and support during this transition.

Thanks to Paul Wise for the tip.

The kernel's swap subsystem is charged with managing anonymous pages in secondary storage when those pages are (hopefully) not being used and the memory they occupy is needed elsewhere. This long-unloved subsystem has seen a resurgence of developer interest in recent times, so it is not surprising that it was the topic of three separate sessions in the memory-management track at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit. Two of those sessions were concerned with improving the performance and maintainability of the swap code, while one (shared with the storage track) was about how swapping could be friendlier to solid-state storage devices.

Security updates have been issued by AlmaLinux (freerdp, gimp:2.8, jq, kernel, and rsync), Debian (chromium, ffmpeg, firewalld, kernel, nginx, openjpeg2, openssh, php7.4, and redis), Fedora (apptainer, chromium, coturn, dnsmasq, firefox, kernel, libgit2_1.8, libmetal, nginx, nginx-mod-brotli, nginx-mod-fancyindex, nginx-mod-headers-more, nginx-mod-js-challenge, nginx-mod-modsecurity, nginx-mod-naxsi, nginx-mod-vts, open-amp, perl-Net-CIDR-Lite, pgbouncer, pypy, python-jupytext, python-uv-build, rsync, rust-astral-tokio-tar, uriparser, uv, valkey, and yelp), Mageia (dpkg, firefox, thunderbird, golang, haproxy, and samba), Slackware (dnsmasq and kernel), and SUSE (apache-commons-configuration2, apache2, apptainer, chromedriver, cups-filters, curl, dnsmasq, expat, ffmpeg-4, ffmpeg-7, firebird, firewalld, flux2-cli, glibc, go1.25, go1.26, gosec, grub2, ImageMagick, java-11-openj9, java-17-openj9, java-1_8_0-openj9, java-1_8_0-openjdk, java-21-openj9, java-25-openj9, kdenlive, kernel, kernel-devel, keylime-config, krb5, libIex-3_4-33, mozjs115, mozjs78, nginx, openssh, openvswitch, ovmf, PackageKit, perl-Crypt-URandom, perl-CryptX, perl-libwww-perl, perl-Net-CIDR-Lite, perl-Text-CSV_XS, podman, postgresql17, postgresql18, python-pyOpenSSL, python310, rsync, sed, tekton-cli, valkey, xen, and zypper-docker).

The 7.1-rc4 kernel prepatch is out for testing.

Some of the documentation updates might be worth highlighting: the continued flood of AI reports has basically made the security list almost entirely unmanageable, with enormous duplication due to different people finding the same things with the same tools. People spend all their time just forwarding things to the right people or saying "that was already fixed a week/month ago" and pointing to the public discussion.

Which is all entirely pointless churn, and we're making it clear that AI detected bugs are pretty much by definition not secret, and treating them on some private list is a waste of time for everybody involved - and only makes that duplication worse because the reporters can't even see each other's reports.

(He is referring to this pull request with patches from Willy Tarreau defining what constitutes a security bug and responsible ways to use AI to find bugs).

We have received word that Peter G. Neumann, who, among many other things, ran the RISKS Digest for decades, has passed away. He will be much missed.

The 7.0.9, 6.18.32, 6.12.90, and 6.6.140 stable kernels have been released. Each contains yet another set of important fixes.

Roman Gushchin began his session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit by saying that the community has seen a lot of proposals adding BPF-based interfaces for memory management. None of them have made their way into the mainline, though. He wanted to explore the ways in which BPF might be helpful and the obstacles that have kept BPF-based solutions out so far. This session was followed by a discussion led by Shakeel Butt on what the requirements for a new, BPF-based interface for memory control groups might look like.

Greg Kroah-Hartman has announced the 7.0.8, 6.18.31, 6.12.89, 6.6.139, 6.1.173, 5.15.207, and 5.10.256 stable kernels. These kernels contain a patch for CVE-2026-46333 a vulnerability reported by the Qualys Security Advisory team, though Jann Horn proposed a patch in 2020. The vulnerability has a proof-of-concept exploit published already. Some of the kernels have additional patches for other bugs; as always, users are advised to upgrade.

Recent times have seen a lot of effort put into the implementation of the kexec handover and live update orchestrator features in the Linux kernel. But that work is not yet complete. At the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Pratyush Yadav led a memory-management-track session on adding the ability to preserve hugetlbfs-provided memory during the live-update process.

Security updates have been issued by Debian (ffmpeg, gsasl, nodejs, postgresql-15, postgresql-17, python3.9, and thunderbird), Fedora (expat, firefox, freerdp, GitPython, kernel, php, rust-podman-sequoia, rust-rpm-sequoia, rust-sequoia-chameleon-gnupg, rust-sequoia-git, rust-sequoia-keystore-server, rust-sequoia-octopus-librnp, rust-sequoia-openpgp, rust-sequoia-sop, rust-sequoia-sq, and rust-sequoia-sqv), Mageia (awstats, libreoffice, perl-HTTP-Tiny, and tomcat), Oracle (corosync, freerdp, gimp, git-lfs, glib2, jq, kernel, krb5, libsoup3, libtiff, openexr, thunderbird, uek-kernel, and yggdrasil), Red Hat (podman and skopeo), SUSE (amazon-ssm-agent, avahi, c-ares, cairo, containerd, cpp-httplib, dnsmasq, dovecot24, ffmpeg-4, firefox, helm, ImageMagick, iproute2, kernel, krb5, libtpms, ongres-scram, ongres-stringprep, plexus-testing, maven, maven-doxia, mojo-parent, sisu, openCryptoki, openssh, perl-Text-CSV_XS, php8, python-lxml, python-Twisted-doc, python311-click, python311-GitPython, rclone, regclient, and syncthing), and Ubuntu (avahi).