wifi: mac80211: take lock before setting vif links

ieee80211_vif_set_links requires the sdata->local->mtx lock to be held.
Add the appropriate locking around the calls in both the link add and
remove handlers.

This causes a warning when e.g. ieee80211_link_release_channel is called
via ieee80211_link_stop from ieee80211_vif_update_links.

Fixes: 0d8c4a3c ("wifi: mac80211: implement add/del interface link callbacks")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230608163202.fa0c6597fdad.I83dd70359f6cda30f86df8418d929c2064cf4995@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -4865,11 +4865,16 @@ static int ieee80211_add_intf_link(struct wiphy *wiphy,
 				   unsigned int link_id)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+	int res;
 
 	if (wdev->use_4addr)
 		return -EOPNOTSUPP;
 
-	return ieee80211_vif_set_links(sdata, wdev->valid_links);
+	mutex_lock(&sdata->local->mtx);
+	res = ieee80211_vif_set_links(sdata, wdev->valid_links);
+	mutex_unlock(&sdata->local->mtx);
+
+	return res;
 }
 
 static void ieee80211_del_intf_link(struct wiphy *wiphy,
@@ -4878,7 +4883,9 @@ static void ieee80211_del_intf_link(struct wiphy *wiphy,
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 
+	mutex_lock(&sdata->local->mtx);
 	ieee80211_vif_set_links(sdata, wdev->valid_links);
+	mutex_unlock(&sdata->local->mtx);
 }
 
 static int sta_add_link_station(struct ieee80211_local *local,