The kernel's file-I/O subsystems have been highly optimized over the years in the hope of providing the best performance for a wide variety of workloads. There is, however, one workload type that suffers with current kernels: applications that perform many short reads, in multiple processes, from the same file. Kiryl Shutsemau has been working on a patch to try to optimize this case, but the task is turning out to be harder than one might expect.

The Universal Blue project has announced the Fall update for the Fedora-based Bazzite gaming distribution. This release brings Bazzite up to Fedora 43, includes support for additional handheld gaming systems, as well as drivers for a number of steering wheel devices, and more.

Security updates have been issued by AlmaLinux (java-21-openjdk and libtiff), Debian (pdns-recursor and xorg-server), Fedora (bind, bind-dyndb-ldap, dtk6core, dtk6gui, dtk6log, dtk6widget, fcitx5-qt, fluidsynth, gammaray, kddockwidgets, LabPlot, mingw-qt6-qt3d, mingw-qt6-qt5compat, mingw-qt6-qtactiveqt, mingw-qt6-qtbase, mingw-qt6-qtcharts, mingw-qt6-qtdeclarative, mingw-qt6-qtimageformats, mingw-qt6-qtlocation, mingw-qt6-qtmultimedia, mingw-qt6-qtpositioning, mingw-qt6-qtscxml, mingw-qt6-qtsensors, mingw-qt6-qtserialport, mingw-qt6-qtshadertools, mingw-qt6-qtsvg, mingw-qt6-qttools, mingw-qt6-qttranslations, mingw-qt6-qtwebchannel, mingw-qt6-qtwebsockets, nheko, python-pyqt6, qt-creator, qt6, qt6-qt3d, qt6-qt5compat, qt6-qtbase, qt6-qtcharts, qt6-qtcoap, qt6-qtconnectivity, qt6-qtdatavis3d, qt6-qtdeclarative, qt6-qtgrpc, qt6-qthttpserver, qt6-qtimageformats, qt6-qtlanguageserver, qt6-qtlocation, qt6-qtlottie, qt6-qtmqtt, qt6-qtmultimedia, qt6-qtnetworkauth, qt6-qtopcua, qt6-qtpositioning, qt6-qtquick3d, qt6-qtquick3dphysics, qt6-qtquicktimeline, qt6-qtremoteobjects, qt6-qtscxml, qt6-qtsensors, qt6-qtserialbus, qt6-qtserialport, qt6-qtshadertools, qt6-qtspeech, qt6-qtsvg, qt6-qttools, qt6-qttranslations, qt6-qtvirtualkeyboard, qt6-qtwayland, qt6-qtwebchannel, qt6-qtwebengine, qt6-qtwebsockets, qt6-qtwebview, unbound, xorg-x11-server-Xwayland, and zeal), Oracle (kernel and libtiff), Red Hat (redis:6), Slackware (tigervnc and xorg), SUSE (java-21-openjdk, java-25-openjdk, strongswan, and xorg-x11-server), and Ubuntu (amd64-microcode, binutils, and xorg-server, xwayland).

Inside this week's LWN.net Weekly Edition:

• Front: Pixnapping attack; Fil-C; Debian ftpmasters; GoFundMe complaints; Safer user-space access.
• Briefs: Man pages 6.16; Btrfs on AlmaLinux; Fedora Linux 43; ICANN report; PSF grants; Rust Coreutils 0.3.0; Tor Browser 15.0; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

Alejandro Colomar has announced the release of version 6.16 of the GNU/Linux man pages. This release includes new or rewritten man pages for fsconfig(), fsmount(), and fsopen(), as well as a number of newly documented interfaces in existing man pages. The release is also available as a PDF book.

ICANN's Security and Stability Advisory Committee (SSAC) has announced a report on "the critical role of Free and Open Source Software (FOSS) within the Domain Name System (DNS)". The report is aimed at policymakers and examines recent cybersecurity regulations in the US, UK, and EU as they apply to FOSS in the DNS system; it includes findings and guidelines "to strengthen the FOSS ecosystem that is critical to the secure and stable operation of the Internet". From the report's summary:

This ecosystem depends on a global network of maintainers and contributors who are often unpaid volunteers. While many are unpaid volunteers, the DNS space is unique in also relying on a handful of long-lived maintenance organizations. This creates a model based on community collaboration rather than the commercial contracts that define a traditional software supply chain, which introduces unique risks related to financial sustainability for the maintenance organizations and maintainer burnout for volunteers.

These unique characteristics mean that regulatory frameworks designed for proprietary software may not be well-suited for FOSS and therefore could have severe unintended consequences to the stability of critical Internet infrastructure.

Thanks to SSAC member Maarten Aertsen for the tip.

A new class of attacks on Android phones, called "Pixnapping", was announced on October 13. It allows a malicious app to gather output rendered in a victim app, pixel-by-pixel, by exploiting a GPU side-channel. Depending on what the victim app displays, anything from sensitive email and chats to two-factor authentication (2FA) codes could be captured—and shipped off to an attacker's site.

Version 15.0 of the Tor Browser has been released:

This is our first stable release based on Firefox ESR 140, incorporating a year's worth of changes that have been shipped upstream in Firefox. As part of this process, we've also completed our annual ESR transition audit, where we reviewed and addressed around 200 Bugzilla issues for changes in Firefox that may negatively affect the privacy and security of Tor Browser users. Our final reports from this audit are now available in the tor-browser-spec repository on our GitLab instance.

This release inherits the vertical tabs feature, unified search button, as well as other new features and usability improvements in Firefox that have passed the Tor Project's audit.

Debian's ftpmaster team has been responsible for allowing new packages to enter Debian, removing old packages, and otherwise maintaining Debian's package archive for more than two decades. As of October 26, the team is no more and its duties are being split between two new teams. The Archive Operations Team will focus on the infrastructure required to support the Debian archives, and the DFSG, Licensing & New Packages Team, which is responsible for reviewing packages entering the new queue. In time, this move could speed up processing of new packages, as well as making the teams more sustainable, but only after new members are recruited and trained. For now, the same folks are doing the work but spread across two teams.

Greg Kroah-Hartman has announced the release of the 6.17.6, 6.12.56, 6.6.115, 6.1.158, 5.15.196, 5.10.246, and 5.4.301 stable kernels. As always, each contains important fixes throughout the tree. Users of these kernels are advised to upgrade.

Security updates have been issued by Debian (gimp, python-authlib, and xorg-server), Fedora (chromium and git-lfs), Mageia (poppler and tomcat), Red Hat (kernel, kernel-rt, redis, and redis:6), SUSE (fetchmail, grafana, ImageMagick, kernel-devel, libluajit-5_1-2, proxy-helm, python-Authlib, and xen), and Ubuntu (linux-intel-iotg, linux-intel-iotg-5.15 and squid, squid3).

Fil-C is a memory-safe implementation of C and C++ that aims to let C code — complete with pointer arithmetic, unions, and other features that are often cited as a problem for memory-safe languages — run safely, unmodified. Its dedication to being "fanatically compatible" makes it an attractive choice for retrofitting memory-safety into existing applications. Despite the project's relative youth and single active contributor, Fil-C is capable of compiling an entire memory-safe Linux user space (based on Linux From Scratch), albeit with some modifications to the more complex programs. It also features memory-safe signal handling and a concurrent garbage collector.

The Fedora Project has announced the release of Fedora Linux 43, with "what's new" articles for Fedora Workstation, Fedora KDE Plasma Desktop, and Fedora Atomic Desktops.

For those of you installing fresh Fedora Linux 43 Spins, you may be greeted with the new Anaconda WebUI. This was the default installer interface for Fedora Workstation 42, and now it's the default installer UI for the Spins as well.

If you are a GNOME desktop user, you'll also notice that the GNOME is now Wayland-only in Fedora Linux 43. GNOME upstream has deprecated X11 support, and has disabled it as a compile time default in GNOME 49. Upstream GNOME plans to fully remove X11 support in GNOME 50.

See the release notes for a full list of changes in Fedora 43.

Security updates have been issued by AlmaLinux (kernel, kernel-rt, libtiff, squid:4, and thunderbird), Debian (strongswan and webkit2gtk), Fedora (pcre2, qt5-qtbase, squid, unbound, and xen), Mageia (icu and libtpms), Oracle (java-1.8.0-openjdk, java-17-openjdk, java-21-openjdk, kernel, squid:4, and thunderbird), Red Hat (libtiff, squid, squid:4, and webkit2gtk3), SUSE (cmake, dracut-saltboot, erlang, exim, expat, ffmpeg-4, firefox, golang-github-prometheus-alertmanager, haproxy, java-11-openjdk, kernel, libxslt, multi-linux-manager, openssl-3, podman, rabbitmq-server, spacewalk-web, strongswan, and wireshark), and Ubuntu (gst-plugins-good1.0, linux-aws-5.15, radare2, ruby2.3, ruby2.5, ruby2.7, and strongswan).

BPF lets users load programs into a running kernel. Even though BPF programs are checked by the verifier to ensure that they stay inside certain limits, some users would still like to ensure that only approved BPF programs are loaded. KP Singh's patches adding that capability to the kernel were accepted in version 6.18, but not everyone is satisfied with his implementation. Blaise Boscaccy, who has been working to get a version of BPF code signing with better auditability into the kernel for some time, posted a patch set on top of Singh's changes that alters the loading process to not invoke security module hooks until the entire loading process is complete. The discussion on the patch set is the continuation of a long-running disagreement over the interface for signed BPF programs.

The Python Software Foundation, earlier this year, successfully obtained a $1.5 million grant from the US National Science Foundation "to address structural vulnerabilities in Python and PyPI". The actual grant came with some strings attached though, in the form of a requirement not to pursue diversity, equity, and inclusion programs. So the Foundation has withdrawn the proposal rather than agree to terms that run counter to its own mission.

We're disappointed to have been put in the position where we had to make this decision, because we believe our proposed project would offer invaluable advances to the Python and greater open source community, protecting millions of PyPI users from attempted supply-chain attacks. The proposed project would create new tools for automated proactive review of all packages uploaded to PyPI, rather than the current process of reactive-only review.

Version 0.3.0 of Rust Coreutils, part of the uutils project, has been released. This release adds safe directory traversal for several utilities, better error handling, and performance improvements. The project has upgraded its test suite reference from GNU coreutils 9.7 to 9.8, and added 16 new tests. It includes a fix for the date bug that affected automatic updates in Ubuntu 25.10.

Security updates have been issued by Debian (intel-microcode, openjdk-11, openjdk-17, openjdk-21, python-pip, request-tracker4, thunderbird, and tika), Fedora (cef, chromium, complyctl, cri-o1.31, cri-o1.32, cri-o1.33, cri-o1.34, docker-buildkit, docker-buildx, dovecot, fetchmail, gi-docgen, golang-github-facebook-time, insight, mbedtls, mingw-binutils, mingw-python3, mingw-qt5-qtsvg, mingw-qt6-qtsvg, moodle, openssl, perl-YAML-Syck, podman-tui, python-socketio, python-sqlparse, python3.10, python3.11, python3.12, python3.9, qt5-qtsvg, runc, samba, squid, sssd, suricata, valkey, wireshark, wordpress, and yarnpkg), Red Hat (libssh), SUSE (aaa_base, afterburn, bind, chromedriver, chrony, firefox, git, govulncheck-vulndb, grub2, ImageMagick, java-11-openjdk, java-17-openjdk, kernel, libssh, libunbound8, libxslt, micropython, mozilla-nss, netty, open-vm-tools, openbao, p7zip, podman, poppler, python-python-socketio, python-urllib3, ruby2.5, rust-keylime, vim, wireshark, and xen), and Ubuntu (linux-aws-6.14).

Version 3.26.0 of the Valgrind memory-profiling and debugging framework has been released. Notable changes include updated support for the Linux Test Project (LTP) to version v20250930, many new Linux syscall wrappers, and the license for Valgrind has been changed from GPLv2 to GPLv3.

Linus has released 6.18-rc3 for testing. "Things feel fairly normal, and in fact the numbers say it's been a bit calmer than usual, but that's likely just the usual fluctuation in pull request timing rather than anything else".