Re: [GIT PULL] wireless-2025-07-10

[Jakub Kicinski <kuba@kernel.org>]

On Fri, 11 Jul 2025 08:41:28 +0200 Johannes Berg wrote:
> > Some good news and some bad news. Bad news is that this missed today's
> > PR. Good news is that we shipped a bug to Linus which is likely to
> > break nl80211 users:
> > https://lore.kernel.org/all/20250711001121.3649033-1-kuba@kernel.org/
> > so I'm gonna send a second PR tomorrow, with the netlink fix and I'll
> > include your fixes in it. I suppose you may want to wait with the fast
> > forward until then. 
> > Now that I typed this I guess it may be two pieces of bad news..  
> 
> No worries, and thanks for the heads-up, I can wait. I actually really
> hope this was the last pull request for the current -rc cycle anyway,
> but of course now that I said it someone's going to come out of the
> woodwork with a fix ;)
> 
> Re the size problem, nl80211 can indeed create and fill really big SKBs
> if userspace gives a big buffer, which it often does. Looking at it now,
> I'm not sure why we set the rcvbuf to 8KiB in iw? That seems ... odd. It
> looks like I originally did that to _increase_ it, but that seems
> completely off, and my first fix didn't even do anything. Then we fixed
> the call but ...
> 
> Looks like the problem is entirely self-made there, but I guess we still
> have to live with stupid userspace, sorry about that. I can take a
> closer look at it all and try to fix things there, if you think it's
> worth it?

Probably not, unless it's hurting in another way. The well maintained
userspace is usually not what we have to worry about the most with
netlink.

I was holding off replying until the dust has fully settled but it
sounds like Linus is still hitting some hard to pin down regression. 
I don't _think_ it's us any more, so I reckon you're safe to fast
forward.