mac80211: fix sdata->radar_required locking

radar_required setting wasn't protected by
local->mtx in some places. This should prevent
from scanning/radar detection/roc colliding.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -970,9 +970,9 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	/* TODO: make hostapd tell us what it wants */
 	sdata->smps_mode = IEEE80211_SMPS_OFF;
 	sdata->needed_rx_chains = sdata->local->rx_chains;
-	sdata->radar_required = params->radar_required;
 
 	mutex_lock(&local->mtx);
+	sdata->radar_required = params->radar_required;
 	err = ieee80211_vif_use_channel(sdata, &params->chandef,
 					IEEE80211_CHANCTX_SHARED);
 	mutex_unlock(&local->mtx);
@@ -3002,8 +3002,8 @@ static void ieee80211_csa_finalize(struct ieee80211_sub_if_data *sdata)
 	struct ieee80211_local *local = sdata->local;
 	int err, changed = 0;
 
-	sdata->radar_required = sdata->csa_radar_required;
 	mutex_lock(&local->mtx);
+	sdata->radar_required = sdata->csa_radar_required;
 	err = ieee80211_vif_change_channel(sdata, &changed);
 	mutex_unlock(&local->mtx);
 	if (WARN_ON(err < 0))

net/mac80211/chan.c

@@ -196,6 +196,8 @@ static bool ieee80211_is_radar_required(struct ieee80211_local *local)
 {
 	struct ieee80211_sub_if_data *sdata;
 
+	lockdep_assert_held(&local->mtx);
+
 	rcu_read_lock();
 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 		if (sdata->radar_required) {

net/mac80211/ibss.c

@@ -303,6 +303,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 		mutex_unlock(&local->mtx);
 		return;
 	}
+	sdata->radar_required = radar_required;
 	mutex_unlock(&local->mtx);
 
 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
@@ -318,7 +319,6 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	rcu_assign_pointer(ifibss->presp, presp);
 	mgmt = (void *)presp->head;
 
-	sdata->radar_required = radar_required;
 	sdata->vif.bss_conf.enable_beacon = true;
 	sdata->vif.bss_conf.beacon_int = beacon_int;
 	sdata->vif.bss_conf.basic_rates = basic_rates;