wifi: mac80211: fix use-after-free

We've already freed the assoc_data at this point, so need
to use another copy of the AP (MLD) address instead.

Fixes: 81151ce4 ("wifi: mac80211: support MLO authentication/association with one link")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -5124,7 +5124,7 @@ static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata,
 	resp.req_ies = ifmgd->assoc_req_ies;
 	resp.req_ies_len = ifmgd->assoc_req_ies_len;
 	if (sdata->vif.valid_links)
-		resp.ap_mld_addr = assoc_data->ap_addr;
+		resp.ap_mld_addr = sdata->vif.cfg.ap_addr;
 	cfg80211_rx_assoc_resp(sdata->dev, &resp);
 notify_driver:
 	drv_mgd_complete_tx(sdata->local, sdata, &info);