Filesystems seem to be one of those many areas where the problems are well understood, but there is always somebody working toward a better solution. As a result, filesystem development in the Linux kernel continues at a fast pace even after all these years. In recent news, the EROFS filesystem is on the path to gain a useful page-cache-sharing feature, there is a new NTFS implementation on the horizon, and XFS may be about to get an infrastructure for self healing.

Version 1.93.0 of the Rust programming language has been released. Notable changes include in updated version of the bundled musl library, thread-local storage for the global allocator, some asm! improvements, and a number of newly stabilized APIs.

Inside this week's LWN.net Weekly Edition:

• Front: Singularity; fsconfig(); io_uring restrictions; GPG vulnerabilities; slab allocator; AshOS.
• Briefs: Pixel exploit; telnetd exploit; OzLabs; korgalore; Firefox Nightly RPMs; Forgejo 14.0; Pandas 3.0; Wine 11.0; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

Konstantin Ryabitsev has put up a blog post about korgalore, a tool he has written to circumvent delivery problems experienced by kernel developers using the large, centralized email systems.

We cannot fix email delivery, but we can sidestep it entirely. Public-inbox archives like lore.kernel.org store all mailing list traffic in git repositories. In its simplest configuration, korgalore can shallow-clone these repositories directly and upload any new messages straight to your mailbox using the provider's API.

One would assume that most LWN readers stopped running network-accessible telnet services some number of decades ago. For the rest of you, this security advisory from Simon Josefsson is worthy of note:

The telnetd server invokes /usr/bin/login (normally running as root) passing the value of the USER environment variable received from the client as the last parameter.

If the client supplies a carefully crafted USER environment value being the string "-f root", and passes the telnet(1) -a or --login parameter to send this USER environment to the server, the client will be automatically logged in as root bypassing normal authentication processes.

OzLabs is a collection of Australian free-software developers that was, for most of its history, associated with IBM. Members of OzLabs have included Hugh Blemings, Michael Ellerman, Ben Herrenschmidt, Greg Lehey, Paul Mackerras, Martin Pool, Stephen Rothwell, Rusty Russell, and Andrew Tridgell, among others. The OzLabs "about" page notes that, as of January 2026, the last remaining OzLabs members have departed IBM. "This brought to a close the Ozlabs association with IBM". Thus ends a quarter-century of development history.

(Thanks to Jon Masters).

The io_uring subsystem is more than an asynchronous I/O interface for Linux; it is, for all practical purposes, an independent system-call API. It has enabled high-performance applications, but it also brings challenges for code built around classic, Unix-style system calls. For example, the seccomp() sandboxing mechanism does not work with it, causing applications using seccomp() to disable io_uring outright. Io_uring maintainer Jens Axboe is seeking to improve that situation with a rapidly evolving patch series adding a new restrictive mechanism to that subsystem.

Linus has released 6.19-rc6 for testing. "So we finally ended up with a slightly bigger rc than usual for this stage in the release cycle, but it's not _that_ big, and things still seem quite stable and civilized."

The Project Zero blog has a three-part series describing a working, zero-click exploit for Pixel 9 devices.

Over the past few years, several AI-powered features have been added to mobile phones that allow users to better search and understand their messages. One effect of this change is increased 0-click attack surface, as efficient analysis often requires message media to be decoded before the message is opened by the user. One such feature is audio transcription. Incoming SMS and RCS audio attachments received by Google Messages are now automatically decoded with no user interaction. As a result, audio decoders are now in the 0-click attack surface of most Android phones.

The blog entry does not question the wisdom of directly exposing audio decoders to external attackers, but it does provide a lot of detail showing how it can go wrong. The first part looks at compromising the codec; part two extends the exploit to the kernel, and part three looks at the implications:

It is alarming that it took 139 days for a vulnerability exploitable in a 0-click context to get patched on any Android device, and it took Pixel 54 days longer. The vulnerability was public for 82 days before it was patched by Pixel.

Al Viro does not often stray outside of the core virtual filesystem area; when he does, it is usually worthy of note. Recently, he wandered into memory management with this patch series to the slab allocator and some of its users. Kernel developers will often put considerable effort into small optimizations, but it is still interesting to look at just how much effort has gone toward the purpose of avoiding a single pointer dereference in some memory-allocation hot paths.

The 2026 edition of the Linux Storage, Filesystem, Memory Management, and BPF Summit will be held May 4-6 in Zagreb, Croatia. The call for proposals has gone out for anybody who would like to attend this invitation-only meeting. "We are asking that you please let us know you want to be invited by February 20, 2026".

The 6.18.5, 6.12.65, 6.6.120, and 6.1.160 stable updates have been released. They all contain a small patch set fixing a scheduling regression associated with idle balancing; the 6.6.120 and 6.1.60 updates also contain a large set of other important fixes.

The READ_ONCE() and WRITE_ONCE() macros are heavily used within the kernel; there are nearly 8,000 call sites for READ_ONCE(). They are key to the implementation of many lockless algorithms and can be necessary for some types of device-memory access. So one might think that, as the amount of Rust code in the kernel increases, there would be a place for Rust versions of these macros as well. The truth of the matter, though, is that the Rust community seems to want to take a different approach to concurrent data access.

On December 24 2025, Linus Torvalds posted a strongly worded message celebrating a ruling in the ongoing GPL-compliance lawsuit filed against VIZIO by the Software Freedom Conservancy (SFC). This case and Torvalds's response have put a spotlight on an old debate over the extent to which the source-code requirements of the GNU General Public License (version 2) extend to keys and other data needed to successfully install modified software on a device. It is worth looking at whether this requirement exists, the subtleties in interpretation that cloud the issue, and the extent to which, if any, the SFC is demanding that information.

Inside this week's LWN.net Weekly Edition:

• Front: What to expect in 2026; LAVD scheduler; libpathrs; Questions for the TAB; Graphite; 2025 timeline.
• Briefs: shadow-utils 4.19.0; Android releases; IPFire 2.29-199; Manjaro 26.0; curl strcpy(); GNU ddrescue 1.30; Ruby 4.0; Partial GPL ruling; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

Android Authority reports that Google will be reducing the frequency of releases of code to the Android Open Source Project to only twice per year.

A spokesperson for Google offered some additional context on this decision, stating that it helps simplify development, eliminates the complexity of managing multiple code branches, and allows them to deliver more stable and secure code to Android platform developers. The spokesperson also reiterated that Google's commitment to AOSP is unchanged and that this new release schedule helps the company build a more robust and secure foundation for the Android ecosystem.

The release schedule for security patches is unchanged.

The calendar has flipped over to 2026; a new year has begun. That means the moment we all dread has arrived: it is time for LWN to put out a set of lame predictions for what may happen in the coming year. Needless to say, we do not know any more than anybody else, but that doesn't stop us from making authoritative-sounding pronouncements anyway.

The 6.19-rc4 kernel prepatch is out for testing.

So this rc is still a bit smaller than usual, but it's not _much_ smaller, and I think next week is likely going to be more or less back to normal.

Which is all exactly as expected, and nothing here looks particularly odd. I'll make an rc8 this release just because of the time lost to the holidays, not because it looks like we'd have any particular issues pending (knock wood).

Greg Kroah-Hartman has written an overview of how the kernel's security team works.

The members of the security team contain a handful of core kernel developers that have experience dealing with security bugs, and represent different major subsystems of the kernel. They do this work as individuals, and specifically can NOT tell their employer, or anyone else, anything that is discussed on the security alias before it is resolved. This arrangement has allowed the kernel security team to remain independent and continue to operate across the different governments that the members operate in, and it looks to become the normal way project security teams work with the advent of the European Union's new CRA law coming into effect.

Nate Graham looks back at how 2025 went for the KDE project.

Today Plasma is the default desktop environment in a bunch of the hottest new gaming-focused distros, including Bazzite, CachyOS, Garuda, Nobara, and of course SteamOS on Valve's gaming devices. Fedora's Plasma edition was also promoted to co-equal status with the GNOME edition, and Asahi Linux — the single practical option for Linux on newer Macs — only supports KDE Plasma. Parrot Linux recently switched to Plasma by default, too. And Plasma remains the default on old standbys like EndeavourOS, Manjaro, NixOS, OpenMandriva, Slackware and TuxedoOS — which ships on all devices sold by Tuxedo Computers!