mac80211: fix possible memory leak in ieee80211_assign_beacon

Free new beacon_data in ieee80211_assign_beacon whenever
ieee80211_assign_beacon fails

Fixes: 8860020e ("cfg80211: restructure AP/GO mode API")
Fixes: bc847970 ("mac80211: support FTM responder configuration/statistic")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/770285772543c9fca33777bb4ad4760239e56256.1562105631.git.lorenzo@kernel.orgSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -936,8 +936,10 @@ static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
 
 	err = ieee80211_set_probe_resp(sdata, params->probe_resp,
 				       params->probe_resp_len, csa);
-	if (err < 0)
+	if (err < 0) {
+		kfree(new);
 		return err;
+	}
 	if (err == 0)
 		changed |= BSS_CHANGED_AP_PROBE_RESP;
 
@@ -949,8 +951,10 @@ static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
 							 params->civicloc,
 							 params->civicloc_len);
 
-		if (err < 0)
+		if (err < 0) {
+			kfree(new);
 			return err;
+		}
 
 		changed |= BSS_CHANGED_FTM_RESPONDER;
 	}