Re: [PATCH] mac80211: fix race in ieee80211_register_hw()

[Krishna Chaitanya]

On Mon, Apr 6, 2020 at 8:36 PM Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote:
>
> On Mon, 2020-04-06 at 19:55 +0530, Krishna Chaitanya wrote:
>
> > > iw phy0 interface add wlan0 type station
> > > ip link set wlan0 up
> > Ah okay, got it, thanks. Very narrow window though :-) as the
> > alloc_ordered_workqueue
> > doesn't need RTNL and there is a long way to go to do if_add() from
> > user and setup
> > the driver for interrupts.
>
> True, I do wonder how this is hit. Maybe something with no preempt and a
> uevent triggering things?
Probably, it might be specific to the dragonboard410c configuration

> > Again depends on the driver though, it
> > should properly handle
> > pending ieee80211_register_hw() with start().

> It could, but it'd be really tricky. Much better to fix mac80211.
Sure, anyways it is a good change.