Re: [PATCH v2] mac80211: reject station addition if AP or MLO link is inactive

[Johannes Berg]

On Mon, 2026-07-27 at 15:26 +0200, Slawomir Stepien wrote:
> After taking a closer look at this I wonder how AP_VLAN should be handled? Is there a way on
> cfg80211 level to be able to check AP_VLAN's main device state?

Hmm, yeah that might be an issue? I guess in theory it could track it,
but it doesn't.

> My code change would look something like this:
> 
> @@ -9404,6 +9404,12 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
>         case NL80211_IFTYPE_AP:
>         case NL80211_IFTYPE_AP_VLAN:
>         case NL80211_IFTYPE_P2P_GO:
> +               /* Add new station only after the AP and link has been started */
> +               int link = params.link_sta_params.link_id >= 0 ?
> +                          params.link_sta_params.link_id : 0;
> +               if (!wdev->links[link].ap.beacon_interval)
> +                       return -ENETDOWN;
> +
>                 /* ignore WME attributes if iface/sta is not capable */
>                 if (!(rdev->wiphy.flags & WIPHY_FLAG_AP_UAPSD) ||
>                     !(params.sta_flags_set & BIT(NL80211_STA_FLAG_WME)))
> 
> but the NL80211_IFTYPE_AP_VLAN case would not work here, right? Can I just do the checking only for
> NL80211_IFTYPE_AP and NL80211_IFTYPE_P2P_GO and skip NL80211_IFTYPE_AP_VLAN?

Yeah it'd just reject everything, I guess.

I think in practice stations are added at the AP interface first and
then moved to a VLAN, which would argue for actually rejecting
everything being OK anyway - but then that shouldn't be because of this
but rather by just removing the AP_VLAN case there, or so.

Not sure what the best thing would be though.

johannes