Re: [PATCH] um: vector: avoid NULL queue dereference in legacy RX mode

From: Anton Ivanov

Date: Thu May 28 2026 - 04:27:41 EST



On 28/05/2026 09:17, Johannes Berg wrote:
On Thu, 2026-05-28 at 09:00 +0100, Anton Ivanov wrote:
So ... you're effectively saying that the tap transport has been broken
since 6.12, released ~1.5 years ago.
The one I use is raw :) It is the most useful.
Right.

Tap badly needs someone to expose the socket which the kernel uses to implement it. I started writing a kernel helper at some point, but never finished it. It should be able to produce "stupid speeds" with it.

And, yes indeed, this was broken by 612a8c8e0b43ba7e3d0e51f6f76a5fec4912d439 / 2024-07-05 which by the look of it I did not test for tap.

Yeah, I guess I'm just thinking that clearly nobody uses it, the
infrastructure isn't there (as you say), and it was broken for a rather
long time now and nobody complained (that we know of.)

That part of the code also gets hit if you turn off vector RX or TX from the command line, so the patch is needed anyway.


So ... is it worth even keeping it? I'm fine either way, just wondering.

johannes


--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/