wil6210: AP: prevent connecting to already connected station

wmi_evt_connect doesn't check if the connect event is received for
an already connected station.
This can lead to memory leak as a new vring is allocated without
freeing the previously allocated vring and to unexpected behavior
of nl80211 layer due to unexpected notification of a new station.

Add a check in wmi_evt_connect in AP mode to verify that the requested
CID is not associated to an already connected station.
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/wil6210/wmi.c

@@ -487,6 +487,14 @@ static void wmi_evt_connect(struct wil6210_priv *wil, int id, void *d, int len)
 			return;
 		}
 		del_timer_sync(&wil->connect_timer);
+	} else if ((wdev->iftype == NL80211_IFTYPE_AP) ||
+		   (wdev->iftype == NL80211_IFTYPE_P2P_GO)) {
+		if (wil->sta[evt->cid].status != wil_sta_unused) {
+			wil_err(wil, "%s: AP: Invalid status %d for CID %d\n",
+				__func__, wil->sta[evt->cid].status, evt->cid);
+			mutex_unlock(&wil->mutex);
+			return;
+		}
 	}
 
 	/* FIXME FW can transmit only ucast frames to peer */