Linux 6.6's in-kernel SMB networking server graduates

The adjacent merchandise of nan Linux kernel, 6.6, has deed merchandise campaigner status. As usual, it contains a number of caller features, but we deliberation 1 has much imaginable ramifications than each nan others put together.

Linus Torvalds announced kernel 6.6-rc1 past night, and it includes nan KSMBD in-kernel server for nan SMB networking protocol, developed by Samsung's Namjae Jeon. We've covered his activity a fewer times connected The Reg, including arsenic a possible stand-in maintainer for NTFS3 arsenic good arsenic maintaining support for Microsoft's exFAT disk format.

Samsung is simply a important unit successful nan retention market, and Reg sister tract Blocks & Files often covers what nan chaebŏl is up to. Samsung unsocial represents immoderate 17 percent of South Korean GDP.

KSMBD has been astir for a while. Just earlier it was first merged into kernel 5.15, LWN offered a bully explainer connected really nan caller module worked. Kernel 5.15 itself was a significant merchandise for its NTFS support. The very adjacent month, connected Christmas eve of 2022, Linux sysadmins sewage to bask KSMBD's first information exploit. What's changed now is that it has faced sizeable security testing and arsenic a consequence it is nary longer marked arsenic experimental.

It's been developed pinch nan assistance of nan Samba team, which itself documents really to usage it. It's compatible pinch existing Samba configuration files. As nan squad says:

One important quality that results from including this arsenic portion of nan kernel, though, is it intends that KSMBD truthful is covered by type 2 of nan GNU Public licence, aliases GPL2 for short. Samba itself uses GPL type 3, of which Torvalds is not an admirer.

GPL 3 places tighter restrictions connected really codification tin beryllium utilized successful commercialized products. When Samba switched to GPL 3, 1 consequence was that Apple dropped Samba from Mac OS X and replaced it pinch its own, in-house server called SMBX.

This was a important move, because complete time, Mac OS X (as nan Reg FOSS table still tends to telephone it) has gradually been made much and much reliant connected SMB for its web connections. In nan merchandise earlier OS X "Lion," 2009's Mac OS X 10.6, Apple had removed nan AppleTalk web protocol, though nan abstracted AppleTalk Filing Protocol (AFP) complete TCP/IP remained. In Mac OS X 10.9, Apple switched to utilizing SMB by default.

Most recently, successful 2020, Apple removed nan expertise to stock volumes complete nan AFP from macOS 11.

So moreover though macOS is a Unix, and includes support for Unix's ain autochthonal file-sharing protocol, NFS, nan Network File System, it defaults to Microsoft's so-called Common Internet File System instead. With CIFS SMB correct wrong nan Linux kernel, it is conceivable that complete clip this mightiness hap complete successful Linux-land arsenic well.

KSMBD is besides important successful that placing specified halfway server functionality right wrong nan kernel represents a important imaginable onslaught aboveground for crackers. As 1 comment connected Hacker News said "Unless this is formally proven aliases rewritten successful a safer language, you'll person to salary maine successful coagulated golden to usage specified a CVE mill waiting to happen."

• Linus Torvalds couldn't find an excuse to clasp backmost Linux 6.5, truthful present it is
• Fed-up Torvalds suggests disabling AMD's 'stupid' performance-killing fTPM RNG
• Linux has astir half of nan desktop OS Linux market
• Debian dev to nan rescue aft connection to region Itanium from Linux kernel

An perfect campaigner for rewriting it successful Rust, then, to usage nan exciting caller support. The caller bcachefs record system will not beryllium going into kernel 6.6, and its developer is not happy. Perhaps he should hurry up its Rust rewrite, too.

Linux isn't nan first Unix to get an in-kernel SMB server, though. OpenSolaris did nan aforesaid backmost successful 2007, and it's doing fin— Oh wait. Well, not-so-open Solaris is still around, anyway. ®

Bootnote

Current versions of macOS tin still connect to AFP shares connected different computers, and conscionable arsenic this vulture was penning nan paragraph astir nan removal of AFP sharing support, his TrueNAS container started softly burbling arsenic Time Machine began making a backup connected nan server's ZFS RAIDZ, shared complete AFP. However, that excessively is deprecated and will vanish astatine immoderate point.