ISO releases new C++ language standards on a three-year cadence; now that it's been more than a year since the finalization of C++23, we have a good idea of what features could be adopted for C++26 — although proposals can still be submitted until January 2025. Of particular interest is the addition of support for hazard pointers and user-space read-copy-update (RCU). Even though C++26 is not yet a standard, many of the proposed features are already available to experiment with in GCC or Clang.

Greg Kroah-Hartman has announced the release of seven more stable kernels. Versions 6.9.8, 6.6.37, 6.1.97, 5.15.162, 5.10.221, 5.4.279, and 4.19.317 are now available.

Security updates have been issued by Fedora (cockpit, python-astropy, python3-docs, and python3.12), Gentoo (BusyBox, GNU Coreutils, GraphicsMagick, podman, PuTTY, Sofia-SIP, TigerVNC, and WebKitGTK+), Mageia (chromium-browser-stable and openvpn), SUSE (cockpit, krb5, and netatalk), and Ubuntu (kopanocore, libreoffice, linux-aws, linux-oem-6.8, linux-aws-5.15, linux-azure, linux-azure-4.15, linux-lowlatency, linux-lowlatency-hwe-6.5, linux-oracle, linux-starfive-6.5, and virtuoso-opensource).

Random numbers, it seems, can never be random enough, and they cannot be generated quickly enough. The kernel's getrandom() system call might, after years of discussion, be seen as sufficiently secure by most users, but it is still a system call. Linux system calls are relatively fast, but they are necessarily slower than calling a function directly. In an attempt to speed the provision of secure random data to user space, Jason Donenfeld has put together an implementation of getrandom() that lives in the virtual dynamic shared object (vDSO) area.

Security updates have been issued by AlmaLinux (389-ds, c-ares, container-tools, cups, fontforge, go-toolset, iperf3, less, libreoffice, libuv, nghttp2, openldap, python-idna, python-jinja2, python-pillow, python3, python3.11-PyMySQL, qemu-kvm, and xmlrpc-c), Debian (znc), Fedora (firmitas and libnbd), Mageia (dcmtk, krb5, libcdio, and openssh), Oracle (golang, openssh, pki-core, and qemu-kvm), Red Hat (openssh), SUSE (apache2-mod_auth_openidc, emacs, go1.21, go1.22, krb5, openCryptoki, and openssh), and Ubuntu (linux, linux-aws, linux-aws-hwe, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm, linux-oracle, linux, linux-aws, linux-azure, linux-azure-5.4, linux-bluefield, linux-gcp, linux-gkeop, linux-hwe-5.4, linux-ibm, linux-ibm-5.4, linux-iot, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4, linux-xilinx-zynqmp, linux, linux-aws, linux-kvm, linux-lts-xenial, linux, linux-gcp, linux-gcp-6.5, linux-laptop, linux-nvidia-6.5, linux-raspi, linux, linux-gcp, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-xilinx-zynqmp, linux, linux-ibm, linux-lowlatency, linux-nvidia, linux-raspi, linux-aws, linux-aws-6.5, linux-oem-6.5, linux-oracle, linux-oracle-6.5, linux-starfive, linux-aws, linux-azure, linux-azure-5.15, linux-azure-fde, linux-azure-fde-5.15, linux-gke, linux-gkeop, linux-gkeop-5.15, linux-ibm, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-oracle, linux-oracle-5.15, linux-azure, linux-azure, linux-azure-6.5, linux-bluefield, linux-iot, linux-gcp, linux-intel, linux-hwe-5.15, and php7.0 and php7.2).

The LWN.net Weekly Edition for July 4, 2024 is available.

There are a handful of extensions to the "new" mount API that Christian Brauner wanted to discuss as part of a filesystem session at the 2024 Linux Storage, Filesystem, Memory Management, and BPF Summit. In the session, though, the only one that he got to was a followup to last year's discussion on mount-operation monitoring. There is a need for user-space programs to be able to follow mount operations (e.g. mount and unmount) that happen in the system, especially for tools like container managers or systemd.

Debian's proposed tag2upload service would be worthy of an article even if it wasn't so contentious; tag2upload promises a streamlined way for Debian developers using Git to upload packages to the Debian Archive. But tag2upload has been in limbo for years due to disagreement and a communication breakdown between the team behind tag2upload and the ftpmasters team. It took the threat of a General Resolution (GR), weeks of discussion, and more than 1,000 emails to finally move forward.

The Universal Blue project, which produces operating system images based on Fedora's Atomic Desktops, has issued an announcement that manual steps are required to continue receiving updates. Jorge Castro wrote:

If you use Bazzite, Bluefin, Aurora, or any other Universal Blue image (including our toolboxes) then you need to follow the instructions in this announcement in order to ensure that your device is getting updates. We were rotating our cosign keypairs this morning, which is the method that we use to sign our images.

During this process I made a critical error which has resulted in forcing you to take manual steps to migrate to our newly signed images.

This applies to all Universal Blue images released before July 2, 2024. See the full announcement for instructions. LWN covered Bluefin in December, 2023.

In 2016, Oliver Smith reached a point of frustration with the short lifespan of updates for his Android phone. Taking matters into his own hands, he began developing postmarketOS, a Linux distribution for mobile phones. Eight years later, the core team and trusted contributors have grown to twenty individuals, while the latest release, v24.06, now shows support for over 250 devices. Although postmarketOS isn't usable as a day-to-day phone operating system on all of them, it can also enable repurposing devices into compact servers or kiosk machines.

Version 4.10.0 of GNU findutils has been released. Notable changes include allowing find -name / as a valid pattern, and accepting larger UIDs/GIDs for find -user and find -group. It is also once again possible to build findutils on systems with musl-libc.

David Rosenthal looks back at 40 years of the X Window System:

A major reason for Sun's early success was that they in effect open-sourced the Network File System. X11 was open source under the MIT license. I, and some of the other Sun engineers, understood that NeWS could not displace X11 as the Unix standard window system without being equally open source. But Sun's management looked at NeWS and saw superior technology, an extension of the PostScript that Adobe was selling, and couldn't bring themselves to give it away.

Security updates have been issued by AlmaLinux (golang and kernel), Fedora (ghostscript and openssh), Mageia (espeak-ng), Red Hat (389-ds, c-ares, container-tools, cups, fontforge, go-toolset, iperf3, less, libreoffice, libuv, linux-firmware, nghttp2, openldap, pki-core, python-idna, python-jinja2, python-pillow, python3, python3.11-PyMySQL, qemu-kvm, and xmlrpc-c), SUSE (ghostscript, git, libndp, libxml2, openssh, pgadmin4, podman, podofo, postgresql14, postgresql15, postgresql16, python39, squid, and wireshark), and Ubuntu (firefox and openvpn).

Like many kernel subsystems, the Linux security module (LSM) subsystem makes extensive use of indirect function calls. Those calls, however, are increasingly problematic, and the pressure to remove them has been growing. The good news is that there is a patch series from KP Singh that accomplishes that goal. Its progress into the mainline has been slow — this change was first proposed by Brendan Jackman and Paul Renauld in 2020 — and this work has been caught up in some wider controversies along the way, but it should be close to being ready.

Security updates have been issued by AlmaLinux (httpd:2.4/httpd), Arch Linux (openssh), Fedora (cups, emacs, and python-urllib3), Gentoo (OpenSSH), Mageia (ffmpeg, gdb, openssl, python-idna, and python-imageio), Red Hat (golang and kernel), SUSE (booth, libreoffice, openssl-1_1-livepatches, podman, python-arcomplete, python-Fabric, python-PyGithub, python- antlr4-python3-runtime, python-avro, python-chardet, python-distro, python- docker, python-fakeredis, python-fixedint, pyth, python-Js2Py, python310, python39, and squid), and Ubuntu (cups and netplan.io).

While the end of support for CentOS 7, which happened on June 30, is significant, it is also worth taking a moment to reflect on the end of Scientific Linux 7, which has also just occurred. Scientific Linux was once a popular RHEL rebuild supported by Fermilab, CERN, DESY, and ETH Zurich. Development of Scientific Linux stopped with SL7, with the labs switching to CentOS thereafter, but the SL7 release was supported through to the bitter end. Thanks are due to all who built and supported Scientific Linux; you provided a useful and stable platform for many years.

On May 7, Kees Cook sent a proposal to the linux-kernel mailing list, asking for the kernel developers to start working on a way to mitigate unintentional arithmetic overflow, which has been a source of many bugs. This is not the first time Cook has made a request along these lines; he sent a related patch set in January 2024. Several core developers objected to the plan for different reasons. After receiving their feedback, Cook modified his approach to tackle the problem in a series of smaller steps.

Security updates have been issued by Debian (dcmtk, edk2, emacs, glibc, gunicorn, libmojolicious-perl, openssh, org-mode, pdns-recursor, tryton-client, and tryton-server), Fedora (freeipa, kitty, libreswan, mingw-gstreamer1, mingw-gstreamer1-plugins-bad-free, mingw-gstreamer1-plugins-base, mingw-gstreamer1-plugins-good, mingw-poppler, and mingw-python-urllib3), Gentoo (cpio, cryptography, GNU Emacs, Org Mode, GStreamer, GStreamer Plugins, Liferea, Pixman, SDL_ttf, SSSD, and Zsh), Oracle (pki-core), Red Hat (httpd:2.4, libreswan, and pki-core), SUSE (glib2 and kubevirt, virt-api-container, virt-controller-container, virt-exportproxy-container, virt-exportserver-container, virt-handler-container, virt-launcher-container, virt-libguestfs-t), and Ubuntu (espeak-ng, libcdio, and openssh).

OpenSSH 9.8 has been released, fixing an ugly vulnerability:

Successful exploitation has been demonstrated on 32-bit Linux/glibc systems with ASLR. Under lab conditions, the attack requires on average 6-8 hours of continuous connections up to the maximum the server will accept. Exploitation on 64-bit systems is believed to be possible but has not been demonstrated at this time. It's likely that these attacks will be improved upon.

Exploitation on non-glibc systems is conceivable but has not been examined.

There is a configuration workaround for systems that cannot be updated, though it has its own problems. See this Qualys advisory for more details.

Linus has released 6.10-rc6 for testing. "This release continues to be fairly calm, and rc6 looks pretty small. It's also entirely just random small fixes spread all over, with no bigger pattern."