mac80211: clear bssid on auth/assoc failure

ifmgd->bssid wasn't cleared properly in some
auth/assoc failure cases, causing mac80211 and
the low-level driver to go out of sync.

Clear ifmgd->bssid on failure, and notify the driver.

Cc: stable@kernel.org # 3.4+
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -3248,6 +3248,8 @@ int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
 	goto out_unlock;
 
  err_clear:
+	memset(ifmgd->bssid, 0, ETH_ALEN);
+	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
 	ifmgd->auth_data = NULL;
  err_free:
 	kfree(auth_data);
@@ -3439,6 +3441,8 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 	err = 0;
 	goto out;
  err_clear:
+	memset(ifmgd->bssid, 0, ETH_ALEN);
+	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
 	ifmgd->assoc_data = NULL;
  err_free:
 	kfree(assoc_data);