The Linux Foundation will be hosting a live interview with LWN co-founder Jonathan Corbet. The event will take place on Tuesday, June 2 at 8:00AM Pacific daylight time (UTC-7). Registration is open for those who would like to attend.

I recently presented a brief tribute to Andrew Morton at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit; it included a suggestion that reading (or re-reading) his 2004 Ottawa Linux Symposium keynote would be instructive. This talk, given immediately after the Kernel Summit session that decided to fundamentally change the kernel's development model, tells a lot about how the kernel project got to where it is today. The text of that speech was hosted on Groklaw, and has since been replaced by crypto spam, which is rather less useful. In the hopes of preserving this seminal moment, the transcript has been rescued thanks to the Wayback Machine and is presented here.

The mapcount field was created to track the number of mappings (page-table entries) that refer to the given page. Among other things, a mapcount of zero means that the page has no references and can be reclaimed. Maintaining mapcount has become increasingly challenging and expensive as the memory-management system has grown in complexity, so Hildenbrand has been looking for ways to get rid of it. This session was, he said, maybe one of the last times he will have to bring up this topic.

Curl maintainer Daniel Stenberg writes about the stress of keeping up with the current flood of security reports.

This is a never-before seen or experienced pressure on the curl project and its security team members. An avalanche of high priority work that trumps all other things in the project that is primarily mental because we certainly could ignore them all if we wanted, but we feel a responsibility, we have a conscience and we are proud about our work. We feel obliged to fix security problems in the software we have helped shipped to every device on the globe. This is personal to us.

With about half the release cycle left until the pending release ships, we already have twelve confirmed vulnerabilities meaning twelve pending CVE announcements. That's a new project record and it also means we will reach thirty published CVEs in 2026 even before half the calendar year has passed. The projected total amount of curl CVEs published through the whole year is therefore at least double this number!

Huge pages can improve performance by increasing translation lookaside buffer (TLB) utilization and reducing memory-management overhead. Transparent huge pages (THPs) are supposed to make huge-page usage, well, transparent, Nico Pache said at the beginning of his session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit. That transparency has never worked as well as many would like; he has been working on improvements to make it easier for applications to use huge pages on Linux systems. A following session, led by David Hildenbrand, was focused on how THPs could be taken away from processes that are not using them fully.

Joshua Hahn began his session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit by saying that the memory controller for control groups is intended to provide resource allocation, accounting, and protection from interference by other tasks. But it was not really designed for tiered-memory systems; he is looking for a way to improve that situation.

The 7.1-rc5 kernel prepatch is out for testing. Quoth Linus:

I'm not entirely happy about it - most of this is totally trivial stuff to random drivers, which obviously makes it all less scary, but at the same time I'm really not convinced the churn is worth it at rc5 time. These things are "fixes", sure, but at the same time a lot of them are simply so irrelevant that I think they'd be better off in a linux-next tree and get merged during the merge window.

So I think I'll start being a bit more hardnosed about this kind of unnecessary churn this late in the game. We are supposed to look for *regressions*. Non-critical fixes to long-standing issues are simply not appropriate for this late in the release cycle.

End result: this is too big, and this is the heads-up that I'll be pushing back on pointless pull requests with fixes that just aren't that important. And yes, several of these series were triggered by AI code review.

The 7.0.10, 6.18.33, 6.12.91, 6.6.141, 6.1.174, 5.15.208, and 5.10.257 stable kernel updates have all been released. The first four are huge (the 7.0.10 review version had 1,146 commits) while 6.1.174, 5.15.208, and 5.10.257 are small updates for the "Fragnesia" vulnerability.

The kernel's page cache is charged with maintaining pages (or, more correctly, folios) containing copies of data from files in the filesystem; its performance has a big effect on the performance of the system as a whole. One of the key decisions the kernel must make is when to evict folios from the page cache. At the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Tal Zussman ran a memory-management-track session on how the page cache could be better customized for specific workloads. It will not be much of a spoiler to say that it involves BPF.

A major page fault occurs when a process attempts to access a page that is not currently present in RAM; satisfying such faults usually involves I/O, and can thus take some time. When many threads sharing an address space are generating page faults, the result can be significant lock contention while that I/O takes place. During the memory-management track at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Barry Song led a session to try, yet again, to find an enduring solution to this problem.

Security updates have been issued by AlmaLinux (firefox), Debian (chromium, nss, openvpn, and thunderbird), Fedora (cockpit, kernel, and linux-firmware), Oracle (gdk-pixbuf2, kernel, and libsndfile), SUSE (container-suseconnect, cpp-httplib, dnsmasq, firefox, glibc, GraphicsMagick, java-1_8_0-openj9, kernel, mozjs115, php8, python-urllib3, rekor, rootlesskit, rsync, tiff, ucode-intel, util-linux, and xz), and Ubuntu (bind9, bubblewrap, libarchive, linux-intel-iot-realtime, postgresql-14, postgresql-16, postgresql-17, postgresql-18, and xdg-desktop-portal).

Michael Catanzaro has disclosed a command-injection vulnerability affecting a number of GTK-based PDF readers; exploits included:

They contain a script for building malicious polyglot PDFs that are simultaneously both valid PDF files and also valid ELF binaries. When the user opens the PDF in the PDF viewer and clicks on a malicious link embedded in the PDF, the PDF abuses the command injection vulnerability to load itself as a GTK module using the `--gtk-module` command line flag. It can then execute arbitrary code via its library constructor. That flag was removed in GTK 4, which is why the vulnerability is much less serious for Papers than it is for Evince, Atril, and Xreader.

The OpenBSD 7.9 release is out, right on schedule. There is the usual long list of new features, including improved architecture support, CPU scheduling on heterogeneous systems, the ability to hibernate a suspended system after a configurable delay, socket splicing, a __pledge_open() system call giving special access to the C library, and much more. See the announcement and the full changelog for details.

Gregory Price started his session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit by saying that, in current kernels, if a NUMA node has memory, the assumption is that anybody can make use of it. He is trying to implement the opposite policy — to make some memory off-limits for all processes except those designed specifically to use it. The session was used to present his goals and to discuss how they might be implemented.

Security updates have been issued by AlmaLinux (kernel, kernel-rt, and libsndfile), Debian (bind9, evince, firefox-esr, openjpeg2, pdns, and rsync), Fedora (erlang-cowlib, evince, expat, firefox, kernel, mingw-expat, mysql8.0, mysql8.4, nss, opencryptoki, pgadmin4, proftpd, python-django5, python-django6, python-dotenv, rsync, rust-nu, rustup, and strongswan), Oracle (nginx, nginx:1.24, ruby, ruby:3.3, and squid), Slackware (bind and rsync), SUSE (buildah, distribution, distribution-registry, docker, firefox-esr, helm, libpainter0, libsdb2_4_2, postgresql-jdbc, runc, and vim), and Ubuntu (gnutls28, gst-plugins-good1.0, jq, linux-nvidia, linux-nvidia-lowlatency, openvpn, rsync, and unbound).

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).

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.

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.