Two new stable LTS Linux kernels drop Monday, both screaming "must upgrade"
It's a big week for stable Linux. Greg Kroah-Hartman released two large stable kernels and both carry the kind of blunt "must upgrade" warning that makes sysadmins look up from their coffee.
These are no small touch-ups. The 6.18.53 stable-review cycle ran through roughly 1,250 patches, while 6.12.111 carried about 1,102. Each is an LTS branch, which means long-term maintenance plus the kind of serious fixes you really don't want to skip.
He announced both on the stable kernel mailing list. And he didn't mince words: both releases are "quite large," he said, carrying "many important fixes throughout the kernel tree," with users "advised to update." Each branch then made its own direct pitch.
6.18.53 told its users "all of the 6.18 kernel series must upgrade." 6.12.111 said the same about the 6.12 series. That's an unusually strong call to action for routine point releases, though "important fixes throughout the kernel tree" helps explain why.
6.18.53: the newer LTS branch
Linux 6.18 became an LTS kernel on December 3, 2025, when Greg named it the newest long-term support branch. It now shares the LTS fleet with five others: 5.10, 5.15, 6.1, 6.6, and 6.12.
A fair amount of ground moved in this release. Crypto gets a rework across the S390 AES/PAES/PMAC paths and the x86 ARIA-AES-NI assembly. The x86 side also sees changes to the alternative-callsite patching engine and memory protection, plus Intel perf/events instrumentation.
There's a big AMD GPU section as well. The amdgpu driver picks up RAS work, GPU page-table and VM fixes, and more Platform Security Processor progress. Intel's Xe driver gains an i2c subsystem and observability tweaks, while the TTM buffer manager gets a cleanup pass.
Networking is where the numbers get interesting. Intel's idpf driver got a full rewrite of its TX/RX and virtchnl path, and Broadcom's bnxt, Mellanox mlx5, Mediatek, and STMicro's stmmac all saw updates. Storage and virtualization aren't an afterthought either, with NVMe host core changes, dm-raid/raid5 fixes, and zram/virtio work.
Keep in mind that the 6.18.53 stable-review window only opened on September 18, so those 1,250 patches piled up in about three days. That's a lot of queued fix-up activity for a single weekly cycle.
6.12.111: the enterprise workhorse
6.12 has been an LTS kernel since late 2024, but its future just got longer. A February 2026 support extension pushes 6.12 support through December 2028, and it's already the base kernel for Debian 13 and RHEL 10.
This week's release leans security-heavy. AMD KVM SEV secure-encryption virtualization takes a big hit: sev.c alone lost 239 lines in what looks like a substantial scrub. CXL memory-expansion RAS work and a pile of ACPI/ACPICA interpreter fixes round out the top of the diff.
Filesystems get the heaviest attention, with btrfs work across inode, ioctl, direct-io, and qgroup, plus large ceph additions. Networking sees dramatic surgery too, where the old Mediatek-ge-soc.c driver was removed entirely (1,555 lines) and re-added under the name mtk-ge.c.
The Apple Silicon story continues. nvme/host/apple.c lost 182 lines as part of the ongoing Asahi push to bring USB4, Thunderbolt, and storage support to Apple's M-series chips running Linux.
Bluetooth and USB round out the tree, with broad updates to btintel, btusb, btmtk, btrtl, and the xHCI USB host controller driver.
A big chunk to absorb, but that's the trade-off for LTS support, and both trees look worth it.
Before this week's releases, Greg published a change to the kernel.org LTS timelines on February 25, laying out the new support windows plainly. The new figures are five: 5.10 for six years, 5.15 for five, 6.6 for four, 6.12 for four, and 6.18 for at least three.
In practice, 6.12 is the biggest winner. It was originally set to die in December 2026 and now gets support through December 2028. That's four years of total life, and it anchors a lot of enterprise deployments.
6.18 started its clock on December 3, 2025 as a two-year window through December 2027, and the extension bumps it to at least three years, so it won't expire until at least December 2028. The older 5.4 series already reached end-of-life with 5.4.302, having lived more than six years since November 2019.
Enterprise distros still stretch this much further by backporting. RHEL tracks kernels for over ten years, SUSE offers up to 16 years with SLES 16, and Canonical supports Ubuntu LTS kernels for up to 15 years with add-on packages.
So why the "must upgrade" language isn't just window dressing. Both trees bundle security fixes across an attack surface that includes confidential computing (AMD KVM/SEV, x86 and powerpc KVM), cryptography (S390 and x86 paths, plus ACPI/EFI CPER handling), and filesystems like btrfs and ceph that have a real history of local privilege-escalation bugs.
Networking drivers, USB, Bluetooth, GPU, and storage drivers are all in the mix too.
Here's one thing that stands out: no single catastrophic regression was flagged by Linus Torvalds. The pattern this week matches recent ones, a large stable release full of scattered but meaningful fixes rather than one big bomb.
The broader context is worth a thought. Mainline itself is now enormous, with Linux 7.3-rc1, released August 30, pushing the tree past roughly 40.98 million lines of code, and releases still cycling every nine or ten weeks. AI/LLM tooling is increasingly used to spot the defects that land in these stable trees, which is probably why these weekly cycles stay so large.
Linux kernel 6.12.111 released
Linux kernel version 6.12.111 is now available:
Full source: https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.12.111.tar.xz
Patch: https://cdn.kernel.org/pub/linux/kernel/v6.x/patch-6.12.111.xz
PGP Signature: https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.12.111.tar.sign
You can view the summary of the changes at the following URL:
https://git.kernel.org/stable/ds/v6.12.111/v6.12.110
Linux kernel 6.18.53 released
Linux kernel version 6.18.53 is now available:
Full source: https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.18.53.tar.xz
Patch: https://cdn.kernel.org/pub/linux/kernel/v6.x/patch-6.18.53.xz
PGP Signature: https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.18.53.tar.sign
You can view the summary of the changes at the following URL:
https://git.kernel.org/stable/ds/v6.18.53/v6.18.52
