There are many possible programmer mistakes that are not caught by the minimal checks specified by the C language; among those is passing an array of the wrong size to a function. A recent attempt to add some safety around array parameters within the crypto layer involved the use of some clever tricks, but it turns out that clever tricks are unnecessary in this case. There is an obscure C feature that can cause this checking to happen, and it is already in use in a few places within the kernel.

Linus Torvalds released the 6.18 kernel as expected on November 30, closing the last full development cycle of 2025. It was another busy cycle, featuring a record number of developers. The time has come for a look at where the code came from for this kernel release, but also for the year-long long-term-support cycle which has also reached its conclusion with this release.

Security updates have been issued by AlmaLinux (bind9.18, cups, gimp, ipa, kernel, libssh, mingw-expat, openssl, pcs, sssd, tigervnc, and valkey), Debian (gnome-shell-extension-gsconnect, mistral-dashboard, pagure, python-mistralclient, pytorch, qtbase-opensource-src, sogo, tryton-server, and unbound), Fedora (cef, drupal7, glib2, linux-firmware, migrate, pack, pgadmin4, rnp, and unbound), Slackware (libxslt), SUSE (cpp-httplib, curl, glib2, grub2, kernel, libcoap-devel, libcryptopp, libwireshark19, postgresql15, and postgresql17), and Ubuntu (edk2).

Greg Kroah-Hartman has announced the release of the 6.17.10, 6.12.60, and 6.6.118 stable kernels. As usual, each contains a number of important fixes throughout the tree. Users are advised to upgrade.

Linus has released the 6.18 kernel, as expected.

So I'll have to admit that I'd have been happier with slightly less bugfixing noise in this last week of the release, but while there's a few more fixes than I would hope for, there was nothing that made me feel like this needs more time to cook. So 6.18 is tagged and pushed out.

Headline changes in this release include the ability to manage namespaces with file handles, support for the AccECN congestion-control protocol, initial support for signing of BPF programs, improved memory management with sheaves, the Rust binder driver, better control over transparent huge pages, and a lot more. This release also saw the removal of the bcachefs filesystem.

See the LWN merge-window summaries (part 1, part 2) and the KernelNewbies 6.18 page for more information.