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>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index b98dc8c..27fa53b 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -970,9 +970,9 @@
 	/* 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 @@
 	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))
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index f43613a..42c6592 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -196,6 +196,8 @@
 {
 	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) {
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 82d3d14..f01d468 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -303,6 +303,7 @@
 		mutex_unlock(&local->mtx);
 		return;
 	}
+	sdata->radar_required = radar_required;
 	mutex_unlock(&local->mtx);
 
 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
@@ -318,7 +319,6 @@
 	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;