lwn.net

One of the many objectives of the Linux Kernel Self-Protection Project (KSPP), which just completed ten years of work, is to ensure that all array references can be bounds-checked, even in the case of flexible array members, the size of which is not known at compile time. One of the most challenging flexible array members in the kernel is not even declared as such. Almost exactly one year ago, LWN looked at the effort to increase safety around the networking subsystem's heavily used sockaddr structure. One year later, Kees Cook is still looking for a way to bring this work to a close.

Security updates have been issued by Debian (keystone and lxd), Fedora (docker-buildkit, firefox, gh, gitleaks, lasso, runc, and seamonkey), Mageia (perl-Authen-SASL, perl-Cpanel-JSON-XS, perl-Crypt-OpenSSL-RSA, perl-JSON-XS, python-flask-cors, python-py, python-setuptools, and ruby), Oracle (java-1.8.0-openjdk), SUSE (binutils, cargo-packaging, rust-bindgen, chromium, go-sendxmpp, helm, lasso, libxml2, openssh, openssh8.4, python-Django, python-Scrapy-doc, python311-Brotli, squid, tomcat10, and weblate), and Ubuntu (linux-nvidia-6.8, linux-oracle, linux-oracle-6.8 and linux-xilinx-zynqmp).

Greg Kroah-Hartman has announced the release of the 6.17.8 and 6.12.58 stable kernels. Each contains an important set of fixes. Users are advised to upgrade.

The Google Security Blog has a new post on just how well the use of Rust is working out for the Android project.

We adopted Rust for its security and are seeing a 1000x reduction in memory safety vulnerability density compared to Android's C and C++ code. But the biggest surprise was Rust's impact on software delivery. With Rust changes having a 4x lower rollback rate and spending 25% less time in code review, the safer path is now also the faster one.

The SUSE Security Team has published an in-depth article on its findings after reviewing a D-Bus service contained in LightDM Greeter by KDE (the lightdm-kde-greeter package) for addition to openSUSE Tumbleweed. The team found a privilege escalation from the lightdm service user to root, as well as other attack vectors in the service:

In agreement with upstream, we assigned CVE-2025-62876 to track the lightdm service user to root privilege escalation aspect described in this report. The severity of the issue is low, since it only affects defense-in-depth (if the lightdm service user were compromised) and the problematic logic can only be reached and exploited if triggered interactively by a privileged user.

The fixes are contained in the 6.0.4 release of the project.

Version 145 of the Thunderbird email client has been released. Notable changes in this release include enabling DNS over HTTPS, support for Microsoft Exchange via Exchange Web Services, and quite a few bug fixes. As of 145, the project is no longer shipping 32-bit binaries for Linux on x86.

Many distributions provide support out of the proverbial box for Flatpak packages, but Fedora is unusual in that it also provides, and defaults, to its own repository of Fedora-built Flatpaks. This has been a source of confusion for Fedora users, who expect to get the Flatpak built by the original developers and hosted on Flathub. It has also been a source of conflict with upstream projects, because users complain of bugs in Flatpak packages they are not responsible for. The situation has also frustrated some Fedora developers, who would prefer to offer put Flathub's offerings first. A new complaint that Fedora has apparently used manifests from Flathub to build the packages for Fedora—without giving credit to the original authors—has spurred discussions about Fedora's Flatpaks once again. While no concrete changes are on the table, yet, there may be some movement toward addressing persistent complaints.

Security updates have been issued by Debian (chromium and firefox-esr), Fedora (firefox, rubygem-rack, skopeo, and webkitgtk), Mageia (perl, perl-CPAN, perl-HTTP-Tiny, perl-Data-Entropy, perl-FCGI, perl-File-Find-Rule, perl-YAML-LibYAML, python-tornado, python-urllib3, python-pip, python3, and unbound), Oracle (ipa and kernel), Red Hat (container-tools:rhel8, krb5, openssl, pcs, podman, and runc), Slackware (mozilla), SUSE (binutils, kernel, netty, netty-tcnative, podman, python311-pdfminer, and tomcat11), and Ubuntu (bind9 and linux-aws-6.8).

Inside this week's LWN.net Weekly Edition:

• Front: FUSE performance; Magic kfuncs; Tails Linux; Direct I/O and modifying buffers; Working with bootable containers.
• Briefs: Kernel LLM policy; Firefox 145; FHS; Homebrew 5.0.0; Mastodon 4.5; Public-inbox 2.0.0; Pytest 9.0.0; Quote; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

Version 5.0.0 of the Homebrew package manager for Linux and macOS has been released. Notable changes in this release include download concurrency by default, official support for 64-bit Arm on Linux, and more.

Longtime LWN readers will have encountered the concept of "stable pages" before; it was first covered here nearly 15 years ago. For the most part, the problem that stable pages were meant to solve — preventing errors when user space modifies a buffer that is under I/O — has been dealt with. But recent discussions show that there is one area where problems remain: direct I/O. There is some disagreement, though, over whether those problems are the result of user-space bugs and how much of a performance price should be paid to address them.

Security updates have been issued by AlmaLinux (kernel, kernel-rt, and libtiff), Debian (kernel, libarchive, rust-sudo-rs, and squid), Fedora (chromium, dotnet8.0, forgejo, ruby, and webkitgtk), Oracle (bind, bind9.18, kernel, kernel-uek*, libtiff, and runc), Red Hat (firefox, kernel, and kernel-rt), Slackware (mozilla), SUSE (buildah, colord, containerd, kernel, lasso, libsoup, micropython, ongres-scram, openssh, proxy-helm, uyuni-tools, python-pdfminer.six, qatengine, qatlib, regclient, and runc), and Ubuntu (raptor and raptor2).

Firefox 145 has been released. Notable changes in this release include note-taking features for PDFs viewed in Firefox, enhanced privacy protections, and the ability to access and manage passwords in the sidebar. This release also drops support for 32-bit Linux systems.

Tails is an unusual Linux distribution developed by the Tor Project; it is designed to help users work around internet censorship and avoid surveillance. It is a "portable" operating system that is meant to be run from a USB stick or ISO image and to leave no trace on the computer it was run on. Tails routes connections to the internet over the Tor network and includes a selection of applications and tools suited to working with sensitive documents, communicating securely, and preserving users' anonymity. The tradeoff, of course, is that Tails is less convenient and requires users to learn a new set of tools to avoid compromising their own security and anonymity. Tails 7.1 was released in October, and it seemed like as good a time as any to take it for a spin.

Security updates have been issued by AlmaLinux (bind, expat, kernel, osbuild-composer, qt6-qtsvg, runc, valkey, and xorg-x11-server-Xwayland), Debian (incus), Fedora (cef and dotnet8.0), Mageia (strongswan), Red Hat (fence-agents and python-requests), SUSE (chromium, colord, erlang26, java-1_8_0-openjdk, libsoup, python-django, thunderbird, tiff, and warewulf4), and Ubuntu (intel-microcode and rust-sudo-rs).

Version 2.0.0 of public-inbox, the mail archiving system behind lore.kernel.org and LWN's email archive, has been released. "This release includes several new features and fixes; mostly around improved integration between inboxes and coderepos for solver. Portability and reliability is also improved, especially in the internal process management of lei."

When programs written in BPF (the kernel's hot-loadable virtual-machine bytecode) call kernel functions (kfuncs), it may be useful for those functions to have additional information about the context in which those BPF programs are executing. Rather than requiring it to supply that information, it would be convenient to let the BPF verifier pass that information to the called function automatically. That is already possible, but a recent patch set from Ihor Solodrai would make it more ergonomic. It allows kernel developers to specify that a kfunc should be passed additional parameters inferred by the verifier, invisibly to the BPF program. The discussion included concerns that Solodrai's implementation was unnecessarily complex, however.

Version 9.0.0 of pytest has been released. Notable changes in this release include the addition of subtests, native support for TOML configuration files, and a new strict mode. See the changelog for a complete list of new features, enhancements, and bug fixes.

Security updates have been issued by AlmaLinux (galera and mariadb, kernel, kernel-rt, mingw-libtiff, redis:7, tigervnc, and xorg-x11-server-Xwayland), Fedora (bind, bind-dyndb-ldap, bpfman, chromium, dolphin-emu, dotnet9.0, golang-github-openprinting-ipp-usb, kea, libnbd, luksmeta, python-cloudpickle, python-pydantic, python-pydantic-core, python-uv-build, ruby, ruff, rust-get-size-derive2, rust-get-size2, rust-regex, rust-regex-automata, rust-reqsign, rust-reqsign-aws-v4, rust-reqsign-command-execute-tokio, rust-reqsign-core, rust-reqsign-file-read-tokio, rust-reqsign-http-send-reqwest, singularity-ce, uv, xen, and xorg-x11-server-Xwayland), Mageia (libxml2, libxslt, opencontainers-runc, and xen), Oracle (bind, galera and mariadb, libsoup, linux-firmware, mariadb:10.5, mingw-libtiff, osbuild-composer, qt5-qt3d, tigervnc, and xorg-x11-server-Xwayland), SUSE (chromium, erlang, google-osconfig-agent, govulncheck-vulndb, java-11-openjdk, java-17-openjdk, java-1_8_0-openj9, opentofu, python-djangorestframework-simplejwt, python311-Django, python315, squid, thunderbird, tiff, tomcat, tomcat11, and xen), and Ubuntu (linux-fips, linux-hwe-6.14, and linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx, linux-raspi).

The 6.18-rc5 kernel prepatch is out for testing. "In other words: it all looks just the way I like it at this point: small and boring."