mac80211: properly drop the connection in case of invalid CSA IE

In case the frequency is invalid, ieee80211_parse_ch_switch_ie
will fail and we may not even reach the check in
ieee80211_sta_process_chanswitch. Drop the connection
in case ieee80211_parse_ch_switch_ie failed, but still
take into account the CSA mode to remember not to send
a deauth frame in case if it is forbidden to.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210409123755.34712ef96a0a.I75d7ad7f1d654e8b0aa01cd7189ff00a510512b3@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -1405,11 +1405,8 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 		ch_switch.delay = csa_ie.max_switch_time;
 	}
 
-	if (res < 0) {
-		ieee80211_queue_work(&local->hw,
-				     &ifmgd->csa_connection_drop_work);
-		return;
-	}
+	if (res < 0)
+		goto lock_and_drop_connection;
 
 	if (beacon && sdata->vif.csa_active && !ifmgd->csa_waiting_bcn) {
 		if (res)