Linux Weekly News

Linux provides a system call (mkdir()) to create a directory, and a few variants of open() that can open a directory. There is, however, no system call in Linux that can create and open a directory in a single, race-free call. Jori Koolstra has been working on remedying that situation, most recently by repurposing a set of open() flags that currently return an error. There are, however, concerns that show just how hard it can be to create user-space interfaces that do not present traps for application developers.

Greg Kroah-Hartman has announced the release of the 6.18.41, 6.12.100, 6.6.147, 6.1.180, 5.15.213, and 5.10.262 stable kernels.

Each of these kernels contains a single fix for a use-after-free vulnerability (CVE-2026-64560). Users of these kernels are advised to upgrade.

Security updates have been issued by AlmaLinux (gstreamer1-plugins-bad-free, libtiff, libXfont2, nodejs:22, nodejs:24, and rest), Debian (expat and nss), Fedora (libssh, nginx, nginx-mod-brotli, nginx-mod-fancyindex, nginx-mod-headers-more, nginx-mod-modsecurity, nginx-mod-naxsi, nginx-mod-vts, nodejs24, perl-HTTP-Date, proftpd, squid, unbound, and wordpress), Oracle (c-ares, edk2, freerdp, go-fdo-server, libreswan, mariadb-connector-c, and nginx), SUSE (alloy, apache-commons-lang3, google-guice, maven, maven-resolver, xmvn, apache-sshd, apptainer, avahi, distribution, glib2, go1.26-openssl, go1.25-openssl, go1.24-openssl, go1.23-openssl, go1.22-openssl, go1.26, go1.25, go1.24, go1.23, go1.22, go1.21, gstreamer-plugins-bad, helm, ImageMagick, java-17-openjdk, java-25-openjdk, liboqs, oqs-provider, libssh, nginx, nm-configurator, nmap, openssl-3, openvpn, PackageKit, perl, perl-DBI, perl-HTTP-Date, perl-XML-Bare, python-msgpack-python, python-sh, python-ujson, python-urllib3, runc, samba, sssd, wget, wpa_supplicant, and xen), and Ubuntu (linux-nvidia, linux-nvidia-7.0 and linux-nvidia-6.17).

Inside this week's LWN.net Weekly Edition:

• Front: Hazard pointers; DFSG team; Swap devices; Netkit and BPF; BPF inlined functions; Fedora GRUB; gccrs.
• Briefs: RIP Dan Williams; Debian LLM resolution; Fedora 45 process; Codeberg LLM policy; GCC LLM policy; GNU Binutils 2.47; GNU C Library 2.44; Wayfire 0.11; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

BPF programs use BPF type format (BTF) debugging information in order to determine how to interact with functions in the kernel. Specifically, tracing a kernel function involves finding its address in the kernel's BTF section — but that doesn't work for functions that have been inlined, and therefore don't have a single, specific address. Alan Maguire wants to add information about inlined functions to BTF in order to allow them to be traced, and led a session on that topic at the 2026 Linux Storage, Filesystem, Memory-Management, and BPF Summit.

Greg Kroah-Hartman has announced the release of the 6.12.99, 6.6.146, and 6.1.179 stable kernels. This batch of stable kernels includes a single fix for a regression caused by this commit. Users of those kernels should upgrade.

Leo Sandoval and Marta Lewandowska have put forward a change proposal for Fedora 45, which is expected in October, to provide a separate, slimmed-down version of GRUB for a niche use case. The new package would be in addition to the main GRUB package and would not replace it for the majority of Fedora users. The idea met with some resistance from Fedora contributors who thought that it would be better to use systemd-boot, or another modern bootloader, rather than trying to wrangle GRUB into a suitable state for the use case. The Fedora Engineering Steering Council (FESCo), however, voted to accept the change on July 7.

The GCC steering committee has announced that it has accepted an AI contributions policy recommended by the GCC AI policy working group.

The policy, in part, states that the project will decline any "legally significant contributions which include LLM-generated content or are derived from LLM-generated content". It uses the definition of "legally significant" from the GNU Project maintainer guidelines, which holds that the threshold is "around 15 lines of code and/or text" to qualify as significant for copyright purposes. GCC maintainers may, however, choose to accept legally significant test cases that are generated by an LLM.

The policy does not forbid use of LLMs for research, analysis, bug discovery and reporting, patch review, etc. as long as the output is not included in contributions. The committee says that it expects the policy will evolve and will be revisited periodically.

Security updates have been issued by AlmaLinux (dovecot, go-fdo-client, go-fdo-server, kernel, kernel-rt, and sssd), Debian (calibre, hplip, libraw, and samba), Fedora (btrbk, chromium, gpsd, kronosnet, and restic), Mageia (gstreamer1.0-libav and libslirp), Slackware (libarchive, samba, and seamonkey), SUSE (agama-web-ui, chromium, gimp, glib2, GraphicsMagick, ignition, ImageMagick, java-21-openjdk, libssh, libssh-config, nginx, nmap, nsd, python-urllib3, python313-CherryPy, rsyslog, samba, sssd, valkey, webkit2gtk3, and yq), and Ubuntu (freerdp3, 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-iot, linux-oracle, linux-oracle-5.4, linux-xilinx-zynqmp, linux-azure-fips, linux-ibm, linux-ibm-5.4, linux-kvm, and linux-raspi, linux-raspi-5.4).

The gccrs project, which is creating a Rust frontend for the GCC compiler, has spent the first half of 2026 focusing on compiling the Linux kernel. By testing the compiler against the kernel crates, the development team has made significant progress toward generating correct code for other Rust programs. As detailed in the project's weekly and monthly reports, this effort has uncovered and resolved problems in areas such as attribute handling (described in the report for February), name resolution, and resource management (both detailed in the May report). Currently, the compiler can only handle simple standalone programs, but that situation could change rapidly in the coming months.

Version 0.11 of the wlroots-based Wayfire Wayland compositor has been released. Notable changes include better fractional scaling, per-output ICC profiles, support for additional Wayland protocols, and more.

The DFSG, Licensing & New Packages Team (usually shortened to "DFSG team") was created in October 2025 as part of the ftpmaster team split. Its job is to review packages in the new queue for compliance with the Debian Free Software Guidelines (DFSG), among other things, before the packages are allowed to enter the Debian archive. The change was long in coming, and some questions remained after the split whether it was the right move. Andrew McMillan provided an overview of the team's activities and its current status during DebConf26. While it may be too early to say with certainty, his report suggests that the new division of duties is working out well.

Security updates have been issued by AlmaLinux (grafana and libreswan), Debian (openjdk-11 and openjdk-17), Fedora (opkssh, perl-Mojolicious, and rpm), Mageia (libyang, memcached, nginx, packages, and sqlite3), Oracle (.NET 8.0, acl, buildah, compat-openssl11, compat-poppler022, dogtag-pki, git-lfs, glibc, go-fdo-client, golang, httpd:2.4, jackson-annotations, jackson-core, jackson-databind, jackson-jaxrs-providers, and jackson-modules-base, kernel, libpq, LibRaw, maven:3.8, mysql8.4, nodejs:22, nodejs:24, openssl, podman, poppler, python3.14, samba, sssd, tomcat, tomcat9, vim, and yggdrasil), Red Hat (gstreamer1-plugins-bad-free), SUSE (afterburn, alsa, apache-ivy, avahi, aws-nitro-enclaves-cli, chromium, cifs-utils, cockpit, cockpit-machines, cockpit-packages, cockpit- podman, cockpit-repos, cockpit-subscriptions, containerd, curl, docker-compose, freetype2, gawk, glib2, google-cloud-sap-agent, gpg2, gstreamer-plugins-bad, gzip, helm, ignition, ImageMagick, jackson-annotations, jackson-bom, jackson-core, jackson- databind, jackson-dataformats-binary, jackson-modules-base, jackson-annotations, jackson-core, jackson-databind, java-11-openjdk, jline3, joe, jq, kernel, libgcrypt, libknet-devel, libsoup, libxml2, mariadb-connector-c, mcphost, net-tools, nghttp2, opennlp, openssl-1_0_0, PackageKit, pam, patch, pcr-oracle, perl, perl-DBI, perl-HTTP-Date, python-aiohttp, python-cryptography, python-Pillow, python-pyasn1, python-soupsieve, python-tornado, python-tornado6, python-urllib3, python3, radvd, rust-keylime, s390-tools, shibboleth-sp, sssd, systemd, tiff, vim, and wpa_supplicant), and Ubuntu (FreeIPMI, glibc, linux-aws, linux-aws, linux-raspi, linux-aws-6.8, linux-aws-fips, linux-azure, linux-azure-6.8, linux-azure, linux-oracle, linux-azure-5.15, linux-azure-fde-5.15, linux-oracle-5.15, linux-azure-6.17, linux-azure-fde, linux-azure-fde-6.17, linux-azure-fde-6.8, linux-azure-fips, linux-hwe-6.8, linux-ibm, linux-ibm-6.8, linux-nvidia-tegra, linux-xilinx, linux-oracle-6.17, roc-toolkit, and samba).

The kernel's read-copy-update (RCU) subsystem ensures that data will not be deleted until it is known that there are no threads holding references to it. RCU works well and is widely used throughout the kernel, but it can increase memory use and add significant delays before unused kernel objects are cleaned up. Hazard pointers are an alternative approach to lockless data updates that offers better performance, for some situations at least. The kernel community is currently considering a hazard-pointer implementation by Mathieu Desnoyers and Paul McKenney.

Version 2.47 of GNU Binutils has been released. In addition to the usual bug fixes there are some notable new features in this release including added support for a number of RISC-V standard extensions, a command-line option (-M annotate) which displays the symbol for undefined instructions for AArch64, and more. The 32-bit s390 target has been deprecated with this release.

Security updates have been issued by Debian (chromium, hplip, and linux-6.1), Fedora (firefox, GitPython, google-osconfig-agent, lego, libgit2, libreswan, libwebsockets, moby-engine, p11-kit, pam, python-idna, rust-libgit2-sys, skopeo, systemd, trafficserver, webkitgtk, and xrdp), Mageia (giflib, graphite2, libnfs, vorbis-tools, wget, and yelp), Red Hat (firefox, thunderbird, and webkit2gtk3), and SUSE (amazon-ecs-init, chromedriver, ffmpeg-7, ffmpeg-8, firefox, google-osconfig-agent, gpg2, java-17-openjdk, java-25-openjdk, kernel, libsrt1_5, nginx, perl-HTTP-Date, perl-XML-Bare, proftpd, python-pyasn1, python-soupsieve, python313-astropy, python313-urwid, systemd, thunderbird, and trivy).

The 7.2-rc5 kernel prepatch is out for testing. Linus said: "So it's a bit too big for my liking, but nothing in there strikes me as particularly strange or scary".

The Debian project is considering a general resolution on the use of large language models in the creation of the distribution. There are three alternatives to consider: a total ban on LLM usage, rejecting LLMs "as far as practical", or explicitly allowing LLM usage subject to a set of conditions. The discussion period has just begun; the beginning of the voting period does not yet appear to have been set. Those who want to look over the discussion ahead of the inevitable LWN article can find it over here.

On July 21, the kernel community lost Dan Williams, one of its most beloved contributors. Dave Hansen and Thomas Gleixner, both of whom worked with Williams extensively, have written an obituary and allowed LWN to publish it. He will be deeply missed, but he has left us with a lot to remember him by.

Security updates have been issued by AlmaLinux (compat-openssl11, java-1.8.0-openjdk, java-17-openjdk, kernel, kernel-rt, and sssd), Debian (exim4), Fedora (chromium, dotnet10.0, mbedtls, mupdf, netatalk, python-django5, skopeo, sssd, and wget1), Mageia (libevent and transmission), Oracle (.NET 8.0, 389-ds-base, aardvark-dns, acl, buildah, cifs-utils, dovecot, dracut, galera and mariadb11.8, glibc, hplip, kernel, libxml2, nginx, openexr, podman, postgresql18, rsync, thunderbird, and vim), and SUSE (389-ds, afterburn, agama, alsa, apache-commons-compress, apache-ivy, brotli-java, zstd-jni, avahi, aws-nitro-enclaves-cli, cockpit, cockpit-machines, cockpit-packages, cockpit- podman, cockpit-repos, cockpit-subscriptions, container-suseconnect, containerd, cosign, cryptsetup, curl, dash, dnsmasq, docker, docker-compose, ffmpeg, firefox, freetype2, gawk, gh, glib-networking, glib2, go1.25, go1.25-openssl, go1.26, go1.26-openssl, google-guest-agent, google-osconfig-agent, gpg2, gsasl, gstreamer-plugins-bad, gzip, haproxy, hauler, helm, helm3, ImageMagick, imagemagick, iproute2, java-11-openjdk, java-26-openjdk, jline3, joe, jq, kernel, kernel-devel, krb5, kubevirt, libgcrypt, libpng12, libqt4, libssh2_org, libXfont2, libxml2, mariadb-connector-c, microcode_ctl, multipath-tools, nasm, net-tools, nghttp2, nmap, ntfs-3g_ntfsprogs, openexr, packagekit, pam, patch, perl, perl-DBI, perl-dbi, perl-http-date, perl-libwww-perl, perl-xml-bare, php8, prometheus-ha_cluster_exporter, python-aiohttp, python-cryptography, python-dulwich, python-idna, python-maturin, python-mistune, python-msgpack, python-paramiko, python-Pillow, python-pyasn1, python-soupsieve, python-sqlparse, python-tornado, python-tornado6, python-urllib3, python313, python313-pandas, python314, qemu, radvd, rootlesskit, rpcbind, ruby3.4, runc, s390-tools, shibboleth-sp, sssd, systemd, systemd, systemd-mini, terraform-provider-aws, terraform-provider-azurerm, terraform-provider-external, terraform-provider-google, terraform-provider-helm, terraform-provider-kubernetes, terraform-provid, terraform-provider-susepubliccloud, tiff, tomcat, tomcat10, tomcat11, uriparser, vim, vorbis-tools, wget, wpa_supplicant, xwayland, and yelp).