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[$] Kitty chases the mouse
Kitty is a terminal emulator that runs on Linux, macOS, and the BSDs, which is notable for its speed and features such as image support and advanced font handling. It is under active development; a recent major release adds a new level of mouse support. Here, we will look at some of those features and show how the program can also be used as platform for text-based applications. Kitty is free software, released under the GPLv3.
[$] LWN.net Weekly Edition for July 9, 2026
Posted Jul 9, 2026 1:12 UTC (Thu)The LWN.net Weekly Edition for July 9, 2026 is available.
Inside this week's LWN.net Weekly Edition
- Front: Cryptography API; Iomap explanation; Negative dentries; Faster RCUs and lockless allocation for BPF; Negative dentries; LLMs in memory-management code
- Briefs: Guix vulnerabilities; OpenSSH 10.4; trusted publishing; kernel archive; CalyxOS; Quotes; ...
- Announcements: Newsletters, conferences, security updates, patches, and more.
[$] Progress in modernizing kernel cryptography
At the 2026 Linux Security Summit North America, Eric Biggers spoke about some of the problems with the kernel's cryptography framework, as well as the recent progress in adding library APIs to allow developers to use cryptographic functions without using the traditional crypto API. He walked through a couple of examples to demonstrate the frailty of the original API and showed how the new library API made life easier for developers and kernel maintainers.
[$] Faster RCUs and lockless memory allocation
Puranjay Mohan shared some of the work he's been doing recently on improving the performance of read-copy-update (RCU) at the 2026 Linux Storage, Filesystem, Memory-Management, and BPF Summit; his talk would have been nice context to have earlier in the day when Harry Yoo and Alexei Starovoitov led a session about the new kmalloc_nolock() function that allows for lockless allocation from any kernel context, and which interacts with the RCU subsystem to allow that. This article therefore covers the two sessions together and in the reverse order, to provide that missing context.
[$] The kernel's iomap layer
Conversations about the kernel's filesystem implementations often involve a layer called "iomap", but relatively few people can reliably say what iomap actually is. That is just the kind of gap that LWN exists to fill. In short, iomap handles the mapping between data in the filesystem space (identified by a file of interest, and an offset within that file) and in the storage space (which may be a memory location, or a set of blocks on a storage device). Using that mapping, iomap handles a long list of common, filesystem-related tasks, allowing a lot of boilerplate code to be removed from individual filesystem implementations.
[$] Limiting negative dentries
A number of problems related to negative directory entries (dentries) were the topic of a filesystem-track session at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit. Negative dentries are used to indicate that a file of a given name does not exist in a directory; it is an optimization that short-circuits the lookup of the file name when the answer is already known. Miklos Szeredi led a session that discussed some problems that come from having too many negative dentries for a directory.
[$] Two LLM-assisted memory-management patch sets
The kernel community (like many other free-software projects) has recently seen a large influx of patches developed with the assistance of large language models (LLMs). Those patches tend to come from developers who were previously unknown to the community. At the moment, though, the memory-management developers are evaluating two large patch sets, developed with LLM assistance, that were submitted by established and well-respected developers. The rather different reception accorded to that work may give insights into how LLM-generated contributions will be handled going forward.
LWN.net Weekly Edition for July 2, 2026
Posted Jul 2, 2026 0:18 UTC (Thu)The LWN.net Weekly Edition for July 2, 2026 is available.
Inside this week's LWN.net Weekly Edition
- Front: Xsnow protestware; Git 2.55; Rhombus; kernel hardening; More LSFMM+BPF coverage; 7.2 merge window; Secure Boot certificate expiration; Ceph and Garage; OSPM 2026.
- Briefs: Akrites; Mageia 10; Git 2.55.0; Podman 6.0; systemd v261; Creative Commons chat; Quotes; ...
- Announcements: Newsletters, conferences, security updates, patches, and more.
Efficient access to local storage for BPF programs
When a BPF program is used to filter or redirect packets in the networking subsystem, the program will often want to associate data with each packet as it moves through the kernel. The kernel's local BPF storage API, which associates extra data with some kernel objects, provides a way to do that. (See also the BPF map types that end in STORAGE.) Amery Hung and Jakub Sitnicki led two sessions at the 2026 Linux Storage, Filesystem, Memory-Management, and BPF Summit about how to make accesses to local storage data more efficient. Hung spoke about general performance problems related to locking, while Sitnicki examined the use of local storage in the networking subsystem in particular.
Secure Boot certificate expiration is here
Linux users who have Secure Boot enabled on their systems rely on certificates issued by Microsoft to verify the software used to boot a system is trusted by the user. One of those certificates expired recently, but that will not cause systems that are able to boot to stop doing so. There are situations where the expiration may cause problems, however, and the window for relying on existing signed binaries is shorter than it might appear. Users and administrators will want to stay on top of these changes. Over the last year, part of my job at Microsoft has been to work on this problem. LWN wrote about the certificate expiration in July 2025, and this article follows up with where we are now.
Rust 1.97.0 released
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 for Thursday
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).
OpenMandriva: Statement regarding attempted distribution sabotage
Over on the OpenMandriva
forum, the Linux distribution has reported
sabotage of its repositories by a disgruntled contributor with
administrative credentials. According to "AngryPenguin", an abusive
incident in a distribution Matrix chat led to a user being kicked out of
the chat; that "triggered a cascade of events
", which led to people
resigning from the distribution. Eventually, one of those people used
their administrative privileges to delete part of the distribution's GitHub
repository and to "publish an empty package in the cooker
repository, which obsoleted all gnome and cosmic packages, which could have
damaged the systems of people using gnome or cosmic
".
We are currently working to restore the deleted repositories and restore the functionality of the obsolete packages.[...] We performed a full system audit and, aside from the removed packages, we found no other violations.
Security updates for Wednesday
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).
Woodruff: You shouldn't trust trusted publishing
William Woodruff, better known online as "yossarian", has published a blog post to make the case that users should not place their trust in trusted publishing:
Trusted Publishing is a mechanism for establishing trust between an external machine identity (like a CI/CD workflow) and one or more projects on a package index/registry. The "trust" in "Trusted Publishing" refers to that trust relationship, and not to anything else.
It is not, and cannot be, a signal for package trust or quality. You cannot use it to determine whether a package is safe or "good," and PyPI consciously stymies attempts to misuse it for that purpose by not rendering it as a "green checkmark" or anything else of the sort.
Or as another framing: Trusted Publishing is just a form of authentication. It doesn't tell you anything other than that an upload was authenticated, which all uploads to PyPI are.
LWN covered trusted publishing in June.
Security updates for Tuesday
Security updates have been issued by AlmaLinux (nodejs22 and nodejs24), Fedora (clamav, hplip, kernel, kernel-headers, librabbitmq, mingw-expat, mir, perl-Imager, podman-tui, prometheus-podman-exporter, python-rpds-py, rust-ashpd, rust-busd, rust-gtk4-macros, rust-inferno, rust-quick-xml, rust-reqsign-aws-v4, rust-wayland-scanner, and sandogasa), Oracle (container-tools:rhel8, kernel, mariadb:10.11, mariadb:11.8, nginx, perl:5.32, php, php:7.4, rrdtool, ruby:2.5, ruby:3.3, ruby:4.0, and uek-kernel), Red Hat (kernel, opentelemetry-collector, and python-urllib3), Slackware (c-ares and openssh), SUSE (bind, chromedriver, cryptsetup, s390-tools, dnsmasq, jackson-annotations, jackson-core, jackson-databind, lcms2, pacemaker, perl-Cpanel-JSON-XS, perl-Crypt-SaltedHash, postfix, and python-mistune), and Ubuntu (gnutls28, gzip, openssh, php7.0, python-parsl, python3.10, python3.12, python3.14, request-tracker5, socat, sogo, and tar).
OpenSSH 10.4 released
OpenSSH 10.4 has been released. In addition to a number of security and bug fixes, there are a few notable changes; this release adds experimental support for a composite post-quantum signature scheme combining ML-DSA 44 and Ed25519 as described in this IETF draft. With 10.4, if OpenSSH is compiled with sandbox support it will fail on Linux systems that have not enabled SECCOMP or NO_NEW_PRIVS; prior to this release, sshd would log an error but continue operation. See the release notes for a full list of changes.
Security updates for Monday
Security updates have been issued by AlmaLinux (container-tools:rhel8, grafana, grafana-pcp, kernel, ruby:2.5, and ruby:3.3), Debian (bird3, chromium, kernel, linux-6.1, mediawiki, nginx, openvpn, php-phpseclib, php8.2, php8.4, and sympa), Fedora (7zip, buildah, chromium, clamav, freerdp, leptonica, mariadb10.11, mariadb11.8, nextcloud, nsd, openqa, openvpn, os-autoinst, pdns, pdns-recursor, perl-Crypt-ScryptKDF, podman, python-jupyter-server, and python-streamlink), Mageia (mariadb and yt-dlp), Slackware (libevent, libseccomp, mozilla, mutt, and php82), SUSE (apache2, containerd, dnsmasq, docker, dracut, firewalld-legacy, gimp, glibc, golang-github-docker-libnetwork, google-guest-agent, gstreamer-plugins-bad, helm, kernel, kernel-devel, keybase-client, kitty, krb5, libarchive, libnfs, libslirp, nilfs-utils, openCryptoki, openQA, openssl-3, pacemaker, pcr-oracle, perl-DBI, perl-List-SomeUtils-XS, podman, python-pip, python-pydata-sphinx-theme, python-tornado6, python3-lxml, python311-mistune, python313-joserfc, rmt-server, sg3_utils, systemd, tracker-miners, and xdg-dbus-proxy), and Ubuntu (cifs-utils, linux-nvidia, linux-nvidia-6.17, linux-raspi-realtime, and ncurses).
Kernel prepatch 7.2-rc2
The 7.2-rc2 kernel prepatch is out for
testing. Linus said: "It's Sunday afternoon, and rc2 is out. Things
look very normal - it's not a small rc2, but it's in line with recent
releases, and slightly smaller than rc2 was in 7.1. Let's see how that all
continues, but so far so good.
"
Seven stable kernels for Saturday including two security fixes
Greg Kroah-Hartman has announced the release of the 7.1.3, 6.18.38, 6.12.95, 6.6.144, 6.1.177, 5.15.211, and 5.10.260 stable kernels. Several kernels in this batch include a fix for a vulnerability introduced in the 6.0 kernel in IPv6 (CVE-2026-53362), which could allow an attacker to escape a container and gain root access.
There is also a fix for a use-after-free bug in KVM (CVE-2026-53359) that was introduced in the 2.6.36 kernel. As usual, each stable kernel includes a number of fixes throughout the tree. Users are advised to upgrade.