Linux 6.18 is now officially out, and it’s not just another end-of-year release. Everything points to this version becoming the next Long-Term Support (LTS) kernel for 2025 – the branch that will quietly power servers, clouds, embedded systems and laptops for years to come, often without users even realizing it.

This time, the focus is much less on flashy, user-facing features and much more on deep, structural work: memory management, storage, networking, virtualization and support for modern hardware. While other platforms load up on visual changes and “AI features”, Linux 6.18 doubles down on internal efficiency and long-term robustness.

A Busy Final Week, but Green Light from Torvalds

Linus Torvalds tagged Linux 6.18 at the end of November, admitting he would have preferred a slightly quieter last week of fixes. Even so, nothing in the final batch of patches was serious enough to justify a delay, so the release went out as planned.

Most of the late changes were small bugfixes in drivers and subsystems like Bluetooth, Ceph or AFS. In performance testing published so far, 6.18 has not shown noticeable regressions compared to 6.17, and in some workloads it performs slightly better thanks to the internal cleanups.

With 6.18 done, the merge window for Linux 6.19 opens immediately and will overlap with both the annual Kernel Maintainer Summit and the holiday period. Torvalds has already warned that this could push 6.19 to an eighth release candidate, but that’s a problem for next year. For now, 6.18 is the kernel everyone will be testing – and, in many cases, standardizing on.

Four Cross-Cutting Pillars: Memory, Storage, I/O and Virtualization

A big chunk of the value in Linux 6.18 comes from changes that don’t belong to any one vendor, but to the kernel core itself. Four areas stand out:

Sheaves
A new internal mechanism aimed at improving kernel memory allocation and reducing contention on systems with many threads. The idea is to keep allocation fast and scalable as core counts grow, especially on servers and high-density systems.
dm-pcache
A new Device Mapper target that allows using persistent memory as a cache layer in front of slower block devices. In practice, this can speed up storage workloads by placing hot data on fast media without exposing complex configurations directly to the user.
IOMMU improvements
The IOMMU subsystem gets refinements that reduce overhead when switching contexts and mapping memory for devices. This matters for systems with multiple PCIe devices, GPUs and accelerators, where mapping and unmapping is constant.
Virtualization optimizations
KVM and related code paths are further optimized for hybrid systems and advanced isolation setups. Linux 6.18 also adds better support for control-flow enforcement technologies (CET) on Intel and AMD, and extends features around AMD SEV-SNP for encrypted virtualization.

Together, these changes don’t make for flashy screenshots, but they do make the kernel smoother under heavy, real-world workloads.

File Systems and Networking: Quiet Evolution That Matters

Storage and networking also see substantial but mostly low-profile changes.

On the storage side:

The Bcachefs file system is removed from mainline for now, after a relatively short stay.
XFS enables online fsck by default, a major step toward detecting and correcting inconsistencies without taking systems offline.
Btrfs takes its first steps toward supporting block sizes larger than the system page size – a long-standing request in some high-performance environments.
EXT4 gains support for 32-bit reserved user and group IDs and a new ioctl() interface to fetch and set superblock parameters.
OverlayFS now supports case-folding, useful when a case-insensitive view of the filesystem is needed.

In networking:

The TCP stack introduces initial support for Accurate Explicit Congestion Notification (AccECN), which offers more precise congestion signaling in modern networks.
Swap performance is improved.
NFS servers scale better under load, and UDP receive performance has been tuned for higher throughput scenarios.

Again, none of this will make headlines on its own, but the cumulative effect is more consistent behavior under stress and better efficiency on busy systems.

Hardware Support: Intel, AMD, Apple Silicon and NVIDIA All Move Forward

Beyond the core, Linux 6.18 pushes hardware support forward across several major vendors.

Intel: Wildcat Lake, Alder Lake and Stronger Virtualization

On the Intel side, the new kernel brings:

Display support for the Wildcat Lake platform, part of the Xe3 graphics generation aimed at improving the display pipeline for desktops and laptops.
Official support for two additional Alder Lake-S SoCs, broadening coverage of desktop variants.
Updates to the VT-d IOMMU driver, aligning it with the latest Intel virtualization specifications.
KVM support for virtualizing Intel’s Control-flow Enforcement Technology (CET), enhancing guest security.

There are also tuning changes for hybrid CPUs that reduce the performance penalty of some security mitigations on efficiency cores, allowing better multithread scaling without giving up protections.

AMD: Preparing the Ground for Zen 6 and Tightening Security

For AMD, Linux 6.18 strengthens two main fronts: future CPUs and secure virtualization.

Internal references to upcoming Zen 6 platforms appear in the kernel, a sign that compatibility work is happening ahead of commercial release, both for desktops and EPYC servers.
Guest support for Secure AVIC improves how virtual interrupts are handled in environments using SEV-SNP, AMD’s encrypted virtualization technology.
Hosts gain support for SEV-SNP CipherText Hiding, closing off some potential attack surfaces related to encrypted guests.

Memory reliability also advances with:

An EDAC driver for the AMD VersalNET memory controller, capable of reporting hardware errors from various IP blocks in the fabric.
An EDAC driver for ARM Cortex-A72 cores, aimed at embedded and specialized systems using these CPUs.

Apple: Apple Silicon Takes Another Step with M2 Pro, Max and Ultra

Apple is another big winner in this cycle. Linux 6.18:

Adds explicit support for Apple M2 Pro, M2 Max and M2 Ultra SoCs via new Device Trees. This is a crucial prerequisite for any meaningful progress toward fully usable Linux installations on these machines.
Updates Apple’s DART IOMMU driver to handle 4-level page tables, better matching the memory architecture of Apple Silicon.
Integrates improvements for older Apple hardware, such as A11 and related components (NVMe storage, SART, SPMI), much of it the result of long-running community work.

Support is still far from “install and forget” for the average user, but getting this code into mainline marks a real change of pace. Apple Silicon is no longer an experimental sidebar – it is now part of the standard kernel.

NVIDIA and the Free Driver: Nouveau Leans on GSP Firmware

On the graphics side, the most interesting news is about the free NVIDIA driver, Nouveau:

On Turing and Ampere GPUs, Linux 6.18 now uses the GPU System Processor (GSP) firmware by default when it’s available, improving initialization and unlocking parts of the graphics pipeline that depended on the GSP.

The proprietary NVIDIA driver still follows its own release schedule and is not tied to 6.18, but Nouveau’s growing maturity on recent hardware is good news for those who prefer fully open drivers.

Security, BPF and Device Support: Lots of Small but Useful Details

Linux 6.18 also ships a number of smaller, security-oriented and quality-of-life improvements:

The audit subsystem can now handle multiple Linux Security Modules (LSMs) at the same time, which is useful in hardened environments.
The kernel adds support for signing BPF programs, tightening control over what code can be loaded into the kernel in sensitive deployments.
New HMAC-encrypted transaction support on the TPM bus (TPM2_TCG_HMAC) is present but disabled by default while behavior is refined.
BPF arenas arrive for PowerPC, and Kexec HandOver support is extended to preserve vmalloc allocations across kexec-style reboots.

On the driver and device side:

A new virtio SPI driver allows SPI devices to be exposed to virtual machines.
The kernel now supports the audio jack on Sony’s DualSense PlayStation controller.
HID drivers are extended to handle haptic touchpads, reflecting design trends in modern laptops.
Apple M2 Pro/Max/Ultra support is wired in alongside these changes.

The overall picture is a kernel that keeps up with both mainstream hardware and more exotic setups, without losing sight of security and maintainability.

Likely the Next LTS: What That Means in Practice

Linux 6.18 is the last stable kernel release of the year. Given its timing and feature profile, it is the natural candidate to become the 2025 LTS kernel series, which would be maintained for several years.

If that happens, 6.18 will become the foundation for:

Enterprise and LTS-style desktop distributions.
Embedded systems and appliances that rarely update their kernels.
Long-lived cloud and virtualization platforms.

The final call rests with the kernel maintainers and, in particular, with long-time stable maintainer Greg Kroah-Hartman. His decision will depend on interest and adoption from vendors and large users. For now, Torvalds’ message is simple: “Please do keep testing.” The sooner any edge cases are found, the sooner 6.18 can be trusted as the long-term workhorse many organizations are waiting for.

Frequently Asked Questions About Linux 6.18

What are the main differences between Linux 6.18 and 6.17?
Linux 6.18 focuses heavily on internal robustness and scalability. Key changes include the new sheaves memory mechanism, the dm-pcache Device Mapper target for caching with persistent memory, refinements to IOMMU and virtualization (including CET and Secure AVIC support), and a wide range of improvements to file systems (XFS, Btrfs, EXT4, OverlayFS) and networking (AccECN, better swap, NFS scaling and UDP receive performance).

Will Linux 6.18 definitely be the next LTS kernel?
It’s very likely, but not guaranteed yet. Because it is the last release of the year and is clearly oriented toward stability and modern hardware support, 6.18 is the natural candidate for LTS status. However, only the stable maintainers can officially designate it as such, based on how widely it’s adopted and how well it behaves in production.

What notable new hardware does Linux 6.18 support?
Linux 6.18 brings explicit support for Apple M2 Pro, M2 Max and M2 Ultra SoCs, new Intel Alder Lake-S variants and the Wildcat Lake platform, early groundwork for AMD Zen 6, EDAC drivers for AMD VersalNET and Cortex-A72, improvements to the free Nouveau driver on Turing and Ampere GPUs, and support for devices like the DualSense audio jack and haptic touchpads.

When will Linux 6.18 be available in my Linux distribution?
The source code for Linux 6.18 is already on kernel.org and in Torvalds’ Git tree. Rolling-release distributions (like Arch Linux or openSUSE Tumbleweed) typically adopt new kernels within weeks, once basic testing is complete. More conservative or enterprise distributions will take longer and may wait for additional point releases (6.18.x) before shipping it as a default. The safest approach is to wait until your distribution offers 6.18 in its stable repositories.

vía: lkml.org