Linux Kernel 7.3-rc4 ships: 449 commits, filesystems and WiFi eat the biggest slice
The fourth release candidate for the 7.3 cycle is out, and it's the kind of update that matters more than it looks.
Linus Torvalds just pushed the fourth release candidate for Linux Kernel 7.3, right on the usual weekly cadence. It's not final. It's the integration branch for bug fixes until the next stable release, and 7.3 itself is still weeks away. But behind the unglamorous "rc" label sits roughly 449 commits from about 239 contributors, a size Torvalds himself flagged as "big" and "bigger than usual."
Not the features cycle you were hoping for
Here's the honest read. There are no shiny new features in an -rc. This cycle is about hardening, and a lot of it is the error-path and bounds-check cleanup that quietly stops memory-safety bugs from becoming your problem later.
Torvalds framed the whole thing around two points. First, size. That's expected every cycle. Second, and more interesting, filesystems showed up a lot more than normal.
"This time around it's smb and ntfs," he wrote. "It's just that filesystems in general seem to have been getting more attention recently." He stressed it's not one dominant filesystem doing all the work. It's breadth across the whole filesystem layer.
He also noted drivers still lead, just "not as dominatingly as they sometimes are." His breakdown of the tree: about a third drivers, a third filesystems plus networking, a third "misc" covering architecture fixes and tooling.
There's a wry aside in there worth pausing on. Torvalds called out "a lot of error path cleanup stuff, which various LLM's seem to be pretty good at catching," while noting it "typically isn't going to be all that noticeable in normal use. But hey, if any of the issues hit you, you are going to care." That last line is the whole story of a mature kernel cycle in one sentence.
Who actually did the work
The numbers tell a small-team story with one loud voice at the top. Johannes Berg led the tree with 34 patches, almost all wireless in cfg80211 and mac80211. That's not feature creep. It's the classic "make a hundred edge cases not misbehave" work: don't apply peer rates to off-channel frames, don't drop scan probe requests, don't start a ROC while scanning, reset state when AP startup fails. It's exactly the kind of patching that keeps flaky Wi-Fi from quietly coming back.
Below Berg it spreads thin. Karl Mehltretter and Namjae Jeon each landed 11 patches. Jeon's batch is the filesystem highlight, splitting time between NTFS and ksmbd.
The filesystem hardening is genuinely the story of this release, and it's not cosmetic.
SMB/CIFS. Frank Sorenson delivered 9 patches tightening how the client parses SMB2 compound PDUs. That means fixing a use-after-free on next_buffer, checking NextCommand bounds, validating minimum PDU sizes, accounting for encrypted PDUs, checking DFS referral offsets, and stopping out-of-bounds struct reads in functions like move_smb2_ea_to_cifs() and parse_posix_sids(). Paulo Alcantara added 5 more, closing an SMBD connection leak and handling a WSL reparse-point misalignment.
ksmbd. The in-kernel SMB server got session-expiration semantics and partial normalized-name response fixes from Jeon's batch.
NTFS. An 11-patch wave covered $MFT tail reservation, MFT and ATTRIBUTE LIST repacking, runlist-lock protection for concurrent updates, and robust handling of interrupted or corrupt inode reads. Zhu Tianhao separately fixed a $MFTMirr write offset that spanned multiple folios.
Both SMB and NTFS are network-exposed. SMB in particular is a favorite ransomware entry point. So parsing and bounds hardening here has a security payoff that goes beyond tidy code.
The rest of the tree
Keep in mind that a tree this broad touches nearly every platform running Linux. A quick scan of the shortlog shows it.
Eric Dumazet (10) went after core networking and TCP: preventing tcp_rmem from dropping below 4096, a netlink group-free race, socket locking in sock_gettstamp(), and several skb offset fixes. Kuniyuki Iwashima (9) worked on neighbor-table RCU annotations and a TCP fast-path fix on a closed listener.
Lorenzo Stoakes (6) touched memory management and huge pages, fixing mm->locked_vm accounting, VMA failure unaccounting, and x86 PAT lock fixes to avoid use-after-free during page-table changes. Vernon Yang separately fixed user-space data loss with MADV_FREE plus transparent huge pages.
It doesn't stop there. You've got btrfs space-saving bugs (Filipe Manana, 5), GPU fixes spread across drm/xe, amdgpu, msm, and nouveau, RDMA memory-safety corrections, xfrm/IPsec use-after-free hardening, ARM64 atomic fixes from Mark Rutland, and a misc bulk covering KVM, Bluetooth, input device quirks (including a Surface Pro 11 probe fix), and scheduler cleanup from Tejun Heo.
The WiFi story deserves a quick footnote. It's easy to read "34 patches" as Berg going on a rampage. In practice it's a tightly scoped correctness pass across wireless state machines, the same discipline that shows up in the networking and memory-management fixes above.
What it actually means
This is mainline Linux behaving like a mature project. No features. Just relentless checking across dozens of subsystems, aimed at catching bugs before the 7.3 freeze.
Breadth is the real headline here. 239 contributors touching drivers, filesystems, networking, and multiple architectures means a single -rc essentially spans everything from Android phones to data-center RDMA to Windows file sharing.
It's a lot of work by a fairly small group of people, and a fair chunk of it is the kind of mechanical, well-scoped cleanup that automated tools are now good at catching. That doesn't make it less important. As Torvalds put it, the point is simply that if any of those issues land in your lap, you'll be the one who cares.
Linux kernel 7.3-rc4 released
Linux kernel version 7.3-rc4 is now available:
Full source: https://git.kernel.org/torvalds/t/linux-7.3-rc4.tar.gz
Patch: https://git.kernel.org/torvalds/p/v7.3-rc4/v7.2
You can view the summary of the changes at the following URL:
https://git.kernel.org/torvalds/ds/v7.3-rc4/v7.3-rc3
What's next
7.3-rc5 is expected around September 27, 2026, again on the weekly Sunday schedule. Once the -rc run wraps up, 7.3 enters stable, with incremental .1, .2, and later patches.
