I have just received the shocking news that Dan Williams, a longtime, high-profile kernel developer, has passed away. I knew him primarily through his long service on the Linux Foundation Technical Advisory Board; he was always a strong, thoughtful, and intelligent presence. Dan will be deeply missed.

There is a support effort underway for Dan's family as they come to terms with this loss.

One of the ideas raised at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit (LSFMM+BPF) was the creation of an operations structure for the swap subsystem. Like many parts of the kernel, the swap layer evolved over time, with pieces being added as needed; the end result of this evolution is rarely what one would expect had the subsystem been designed today. The interface between the swap layer and the devices it uses is just one example. It appears that one result of the swap subsystem's evolution — the lack of an abstraction layer to interface with underlying storage — will soon be addressed, but in a different way than was initially envisioned.

The Codeberg forge has adopted a pair of new policies, promising not to use hosted projects to train LLMs and, more controversially, banning the hosting of LLM-generated software. The site's blog describes and justifies these policies.

Although often well intentioned, sharing the result of a prompt and calling it "libre software" does not make the world a better place. Codeberg is not and does not want to be a place to dump such generated single-use software that no one else will ever look at. We are a place for people to collaborate and improve software together. Within this context, the recent votes can be understood as a reconfirmation of those principles: As we want to center on human collaboration, we will not actively support or engage in the creation of LLMs and will not put our limited resources to use for storing single-use software that would pollute our FLOSS commons.

Like many development communities, the kernel community has been struggling to determine how large language models will be used in its development process. The news has been dominated recently by a strongly worded missive from Linus Torvalds on the subject, but the discussion has been rather more wide-ranging and nuanced than that. Topics that have been considered recently include the LLM attribution requirement, code-review tools, dependence on proprietary tools, and whether there is a place for concerns about the ethics of LLMs.

The 7.2-rc4 kernel prepatch is out for testing. Linus said: "This whole week I had the feeling that people were starting to go on summer vacation, but running the numbers shows that I must have been wrong - it all looks pretty normal."

Adrian Mastronardi has released a book called Half a Second; it is a detailed look into the XZ backdoor attempt of 2024. The book is freely available under a (non-free) noncommercial, no-derivatives CC license.

Half a Second tells that story as one continuous narrative: the burned-out volunteer who maintained the code alone and was patiently, expertly manipulated into giving it up; the engineer whose half-second of curiosity caught the attack through a chain of luck and hard-won instinct; and the operator who built it, who has never been identified and, this book argues, may never be.

The 7.1.4, 6.18.39, and 6.12.96 stable kernel updates have been released; each contains a fairly large set of important fixes.

The extensible scheduler class (sched_ext) allows the installation of custom CPU schedulers as a set of BPF programs. While sched_ext, in its current form, has already led to a lot of interesting scheduler-development work, the subsystem itself is still undergoing rapid evolution. Among other work, the ability to set up a hierarchy of sub-schedulers is approaching completion, and a longstanding incompatibility with proxy execution is coming to an end.

Inside this week's LWN.net Weekly Edition:

• Front: Fighting scraper bots; io_uring queues; Filesystem testing; BPF shielding; Sending packets from BPF; Kitty; QBE.
• Briefs: Shim security; seunshare vulnerability; Debian bookworm; Rust 1.97.0; Linux.org; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

Processes that use io_uring tend to keep a lot of balls in the air; being able to have many operations underway at any given time is part of the point of that API in the first place. The io_uring subsystem must, as a result, keep track of a lot of tasks that have to be performed at the right time. In current kernels, io_uring uses a standard kernel linked-list primitive to track those work items. As of the 7.2 kernel release, though, io_uring will, instead, use a new lockless, multi-producer, single-consumer (MPSC) queue, resulting in some notable performance gains. Lockless algorithms tend to be tricky, but the one used here is relatively approachable and shows how these algorithms can work.

The CMU CERT Coordination Center has put out an advisory that many exploitable versions of the shim binary, used to boot Linux on systems with UEFI secure boot enabled, were never added to the revocation list.

An attacker with administrative privileges or the ability to modify the boot process could use one of the vulnerable shim bootloaders to bypass Secure Boot protections and execute arbitrary code before the operating system loads. Code executed during this early boot phase may achieve persistent compromise of the platform, including the ability to load unsigned or malicious kernel components that can survive system reboots and, in some cases, operating system reinstallation.

The advisory contains a list of vulnerable shims.

Rob Kennedy has posted the story of the birth of Linux.org — one of the earliest Linux-related web sites — and its more recent rebirth.

The site was founded in May 1994 by Michael McLagan, at a time when Linux itself was barely three years old. Linus Torvalds had only just released it to the world, there was no real way for a newcomer to find their footing, no search engines, no Wikipedia, none of the infrastructure people take for granted now for figuring out a new piece of technology. Michael built linux.org to fill that gap, a place for people to learn about Linux and follow the movement as it grew.

The Maintainers Summit is an annual, invitation-only gathering of kernel developers and maintainers to discuss development-process issues; see LWN's 2025 Maintainers Summit coverage for an example. The call for topics for the 2026 gathering (Prague, October 8) has gone out. One of the best ways to obtain an invitation to the Summit is with a good topic proposal. For best consideration, topics should be submitted before July 24.

The 7.2-rc3 kernel prepatch is out for testing. Linus said: "Things continue to look normal (the 'new normal' with slightly higher rates of commits, although I do get the feeling that we're seeing that slightly balanced out by people starting to go on summer vacation)".

Our article "Fighting the AI scraper bot scourge", published in early 2025, discussed the problem of widespread scraping of web sites in search of training data for large language models and related projects. This activity overwhelms sites with traffic. Over a year after that article is published, the problem is still growing. The hammering of sites by shadowy actors has reached new heights, and the open web is becoming increasingly difficult to maintain. Where is this traffic coming from, and what can be done about it?

Security updates have been issued by AlmaLinux (aardvark-dns, cups, edk2, gstreamer1-plugins-bad-free, gstreamer1-plugins-good, gstreamer1-plugins-ugly-free, kernel, libsolv, libtasn1, libxml2, nginx:1.24, nginx:1.26, oci-seccomp-bpf-hook, python-urllib3, and tomcat), Debian (rlottie), Fedora (c-ares, k9s, kind, libXfont2, nmap, pam, perl-DBI, php, python-pendulum, tmux, and xorg-x11-server-Xwayland), Mageia (7zip and ack), Slackware (tigervnc), SUSE (alloy, cargo-c, chromium, clamav, cosign, dirmngr, firefox, flannel, fluidsynth, gnutls, go1.25, go1.26, gol, GraphicsMagick, helm, kernel-devel, libaom, libexif, openQA, os-autoinst, python-Django, python-idna, python-sqlparse, rust-keylime, rustup, sccache, SUSE Manager Client Tools, SUSE_Multi-Linux_Manager Client Tools, transmission, and warewulf4), and Ubuntu (curl, expat, golang-go.crypto, libheif, libidn, libraw, libsoup2.4, linux, linux-azure-4.15, linux-azure-fips, linux-fips, linux-gcp-4.15, linux-gcp-fips, linux-kvm, linux-oracle, linux-aws, linux-aws-fips, linux-azure-fips, linux-fips, linux-raspi, linux-xilinx-zynqmp, and python2.7, python3.5).

Version 1.97.0 of the Rust programming language has been released. Changes include using a new symbol-mangling scheme by default, support for denying warnings in Cargo, and an end to the practice of hiding the linker's output after a successful build.

Security updates have been issued by AlmaLinux (389-ds-base, aardvark-dns, buildah, compat-openssl10, freeipmi, frr, gnutls, grafana, grafana-pcp, kernel, kernel-rt, libyang, nginx, openexr, pcs, perl-HTTP-Daemon, postgresql:18, python3.14-pip, skopeo, tomcat9, and wireshark), Debian (chromium and pgextwlist), Fedora (openssh, opkssh, perl-CSS-Minifier-XS, python-jiter, python-nh3, python-pendulum, rust-jiter, and upower), Mageia (openvpn and vips), Oracle (389-ds-base, aardvark-dns, compat-openssl10, container-tools:ol8, freeipmi, kernel, libyang, perl-HTTP-Daemon, python3.14-pip, and skopeo), Slackware (libXfont2, proftpd, and xorg-server), SUSE (alloy, apache2, apptainer, assimp, chromium, clamav, docker, docker-compose, dracut, glib-networking, go-sendxmpp, go1.26-openssl, gstreamer-plugins-good, haproxy, hauler, jackson-annotations, jackson-bom, jackson-core, jackson- databind, jackson-dataformats-binary, jackson-modules-base, jackson-parent, kernel, krb5, kubevirt, libslirp, libXfont2, mpv, libkpipewirerecord6, ffmpegthumbs-kf5, netty, netty-tcnative, openqa, os-autoinst, podman, python-maturin, python-msgpack, python313-yt-dlp, radare2, rust-keylime, systemd, systemd, systemd-mini, tomcat11, trivy, xorg-x11-server, and xwayland), and Ubuntu (apache2, clamav, linux-raspi, and mailcap).

Security updates have been issued by AlmaLinux (container-tools:rhel8, kernel-rt, libreoffice, nodejs:22, nodejs:24, opentelemetry-collector, perl-HTTP-Daemon, and python-markdown), Debian (dpkg, imagemagick, and postfix), Fedora (betterleaks, docker-compose, firefox, helm, perl-Compress-Raw-Bzip2, perl-IO-Compress, perl-JavaScript-Minifier-XS, python-cramjam, python-fastar, python-pillow-jxl-plugin, python-rignore, and tor), Oracle (grafana, grafana-pcp, and ruby:4.0), Slackware (tftp), SUSE (gi-docgen, glibc, helm, helm3, json-c-devel, kubevirt-1.6, librpmbuild10, python313-dulwich, python313-lxml_html_clean, python313-openapi-spec-validator, and sdbootutil), and Ubuntu (ruby-addressable).

Conversations about the kernel's filesystem implementations often involve a layer called "iomap", but relatively few people can reliably say what iomap actually is. That is just the kind of gap that LWN exists to fill. In short, iomap handles the mapping between data in the filesystem space (identified by a file of interest, and an offset within that file) and in the storage space (which may be a memory location, or a set of blocks on a storage device). Using that mapping, iomap handles a long list of common, filesystem-related tasks, allowing a lot of boilerplate code to be removed from individual filesystem implementations.