Linux 7.3 Is out, With a New System Call and a Filesystem That Fails on Purpose
Linus Torvalds tagged Linux 7.3 in the mainline kernel tree on Oct. 18, 2026, closing a development cycle that added a new filesystem, a new system call and a completed scheduler framework. The signed v7.3 tag in Torvalds' tree carries that date, and kernel.org's own release table lists 7.3 as the current mainline release, dated Oct. 18, 2026.
Mainline is the tree that stable and distribution kernels are derived from, so what landed in this cycle is what reaches those kernels next.
LWN.net's release note lists the significant changes. Among them are failfs, a new filesystem that fails every operation asked of it, and the fchroot() system call. LWN also names global per-CPU data for BPF programs, the small programs that can be loaded into a running kernel, and the completion of the sched_ext subscheduler.
The rest of LWN's list runs to group-scheduling work aimed at improving performance on large systems, working-set tracking for virtual machines, extensions to binfmt_misc, alternative data-stream support in ntfs3, the kernel's driver for Windows NTFS disks, and a set of improvements to the kernel's SMB file-sharing server.
The size of the cycle is LWN's count rather than the project's: 18,765 non-merge commits from 3,021 developers, 807 of them contributing to the kernel for the first time. Neither the tag nor kernel.org's release table carries a tally of its own.
In the release announcement LWN reproduced, Torvalds wrote that the merge window for 7.4 opens the day after 7.3 shipped, and that his own merging would run on an unusual schedule while he is away on a family vacation.
