After two weeks of intense work, Linus Torvalds finally tagged and pushed out the first release candidate (RC1) of the upcoming Linux Kernel version 6.18.
The Linux 6.18-rc1 release marks the formal closing of the merge window. Therefore, it gives us a clear look at all the exciting updates coming soon to your Linux systems.
Additionally, Linux 6.18 is anticipated to become this year's Linux LTS (Long-Term Support) kernel version, which makes it particularly significant as it will receive extended maintenance and support.
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A Smooth Ride for the Merge Window
Torvalds shared a positive assessment of this release cycle. In the Linux Kernel 6.18-rc1 announcement mail, he noted that 6.18-rc1 looks fairly normal. In fact, when looking at its size, the kernel sits right in the middle compared to past releases.
Notably, this merge window was exceptionally smooth. Linus reported that he did not need to track down any specific issues on his test machines.
Linus called it "one of the good merge windows". Furthermore, he expressed hope that this testing success will also hold true for the "bigger picture" of kernel stability.
What's New in Kernel 6.18-rc1?
If you look at the Linux 6.18-rc1 shortlog, you'll notice diverse updates across the system. Drivers always form a large part of kernel changes, and this release is no different. Drivers make up about half of the total changes.
The remaining half of the kernel updates touch many core areas. For example, developers merged important changes to the VFS and filesystems. Plus, we see key updates in architectural components, tooling, and even Rust support.
Many core areas saw major contributions from key maintainers:
1. Filesystems and Storage
The 6.18-rc1 release includes updates and fixes for nearly every major filesystem you can name. This encompasses updates for:
- VFS (Virtual Filesystem).
- Popular file systems like xfs, btrfs, ext4, and f2fs.
- Newer or specialized file systems such as ntfs3, exfat, and erofs.
- The kernel also received important NFS client and server updates.
2. Architecture and Hardware Support
The Linux kernel always needs updates to support new hardware and improve existing platforms. Consequently, 6.18-rc1 brought many architectural changes:
- x86 updates are extensive, including improvements to the instruction decoder, microcode loading, mitigation controls, and especially TDX updates.
- Developers pushed updates for virtualization, including KVM updates (for both general KVM and specifically x86 KVM).
- The kernel received patches for modern architectures like RISC-V and arm64.
- Other platforms like s390, MIPS, and powerpc also saw updates.
3. Core Kernel Infrastructure
The underlying engine that keeps Linux running also saw significant improvements:
- The Memory Management (MM) subsystem received multiple updates.
- Developers merged new bpf updates and fixes.
- Updates arrived for kernel security, specifically including seccomp updates and general hardening updates.
- RCU, locking, and scheduler updates help improve how the system handles processes and concurrency.
4. Device Drivers
As noted, drivers form the biggest portion of the changes. This ensures that your hardware runs smoothly. The updates cover a huge range of device types, including:
- USB / Thunderbolt updates and PCI updates.
- Input devices and HID updates.
- Sound updates, as well as firewire and i2c updates.
- SCSI updates and staging drivers also received attention.
What Happens Next?
This release candidate, 6.18-rc1, starts the testing period. Kernel developers and enthusiasts now test this code rigorously to catch bugs.
Hopefully, the smooth start Torvalds saw during the merge window translates into a very stable final 6.18 release!
Test Linux Kernel 6.18 RC1
As with every release, Linus has asked everyone to start testing and fixing. So, if you are a developer or an enthusiastic user, download Linux 6.18-rc1, give it a try, and report any issues you find.
You can get the Kernel 6.18 RC1 from the Kernel.org website or the Linus Torvalds's git tree.
Kernel 6.18 Estimated Final Release Date
The final stable release of Linux Kernel 6.18 is expected to be around the end of November or the beginning of December 2025.
Linux kernel development typically follows a very consistent schedule:
- A 2-week merge window for new features closes, culminating in the release of RC1. This happened on October 12, 2025, for 6.18.
- The kernel then enters a 7-week bug-fixing and stabilization period with a new Release Candidate released almost every week, typically on Sundays (RC2, RC3, …4 RC7).
- The final stable release usually occurs one week after RC7.
Most releases only need seven Release Candidates (RCs), which would put the final release on November 30, 2025.6 If an eighth RC is required due to last-minute issues, the release would likely be delayed one week to December 7, 2025.
So, if the cycle stops at RC7 (the most common case), the final release is at the end of November. If the cycle continues to RC8 (for a release that needs extra bug fixing), the final release is pushed into early December.
