mac80211: mlme: save ssid info to ieee80211_bss_conf while assoc

The ssid info of ieee80211_bss_conf is filled in ieee80211_start_ap()
for AP mode. For STATION mode, it is empty, save the info from struct
ieee80211_mgd_assoc_data, the struct ieee80211_mgd_assoc_data will be
freed after assoc, so the ssid info of ieee80211_mgd_assoc_data can not
access after assoc, save ssid info to ieee80211_bss_conf, then ssid info
can be still access after assoc.
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Link: https://lore.kernel.org/r/1607312195-3583-2-git-send-email-wgong@codeaurora.org
[reset on disassoc]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -2403,6 +2403,8 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
 	/* clear bssid only after building the needed mgmt frames */
 	eth_zero_addr(ifmgd->bssid);
 
+	sdata->vif.bss_conf.ssid_len = 0;
+
 	/* remove AP and TDLS peers */
 	sta_info_flush(sdata);
 
@@ -5518,6 +5520,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_mgd_assoc_data *assoc_data;
 	const struct cfg80211_bss_ies *beacon_ies;
 	struct ieee80211_supported_band *sband;
+	struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
 	const u8 *ssidie, *ht_ie, *vht_ie;
 	int i, err;
 	bool override = false;
@@ -5535,6 +5538,8 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 	}
 	memcpy(assoc_data->ssid, ssidie + 2, ssidie[1]);
 	assoc_data->ssid_len = ssidie[1];
+	memcpy(bss_conf->ssid, assoc_data->ssid, assoc_data->ssid_len);
+	bss_conf->ssid_len = assoc_data->ssid_len;
 	rcu_read_unlock();
 
 	if (ifmgd->associated) {