Re: [PATCH net-deletions] net: remove ax25 and amateur radio (hamradio) subsystem

Dan Cross
2026-04-21T16:18:00Z

On Tue, Apr 21, 2026 at 9:55 AM Stephen Hemminger
<stephen@networkplumber.org> wrote:
> On Mon, 20 Apr 2026 19:18:23 -0700
> Jakub Kicinski <kuba@kernel.org> wrote:
> > Remove the amateur radio (AX.25, NET/ROM, ROSE) protocol implementation
> > and all associated hamradio device drivers from the kernel tree.
> > This set of protocols has long been a huge bug/syzbot magnet,
> > and since nobody stepped up to help us deal with the influx
> > of the AI-generated bug reports we need to move it out of tree
> > to protect our sanity.
> >
> > The code is moved to an out-of-tree repo:
> > https://github.com/linux-netdev/mod-orphan
> > if it's cleaned up and reworked there we can accept it back.
>
> It would be good if these protocols could be done in userspace
> or with BPF?

Consensus for a userspace implementation is what folks on linux-hams
seem to be converging on.

The amateur radio protocols are more or less specific to low-speed
links, they are not particularly coupled to anything else that
requires running in the kernel, and the main coupling point (IP over
AX.25) can be implemented via TAP/TUN.

There are several popular packages that already implement AX.25 and
NET/ROM in user-space (for the interested, LinBPQ seems to be the
canonical example). The main missing piece is ROSE, but it is likely
easier to add that to an existing package, or potentially something
brand new, than keep it in the kernel.

There's no compelling reason to keep these protocols in the kernel,
whether in-tree or out-of-tree; at least, one has not been
articulated.

- Dan C.