ath10k: ensure peer_map references are cleaned up

While debugging OS crashes due to firmware crashes, I enabled
kasan, and it noticed that peer objects were being used-after-freed.

Looks like there are two places we could be leaving stale references
in the peer-map, so clean that up.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/mac.c

@@ -802,6 +802,7 @@ static void ath10k_peer_cleanup(struct ath10k *ar, u32 vdev_id)
 {
 	struct ath10k_peer *peer, *tmp;
 	int peer_id;
+	int i;
 
 	lockdep_assert_held(&ar->conf_mutex);
 
@@ -818,6 +819,17 @@ static void ath10k_peer_cleanup(struct ath10k *ar, u32 vdev_id)
 			ar->peer_map[peer_id] = NULL;
 		}
 
+		/* Double check that peer is properly un-referenced from
+		 * the peer_map
+		 */
+		for (i = 0; i < ARRAY_SIZE(ar->peer_map); i++) {
+			if (ar->peer_map[i] == peer) {
+				ath10k_warn(ar, "removing stale peer_map entry for %pM (ptr %p idx %d)\n",
+					    peer->addr, peer, i);
+				ar->peer_map[i] = NULL;
+			}
+		}
+
 		list_del(&peer->list);
 		kfree(peer);
 		ar->num_peers--;
@@ -828,6 +840,7 @@ static void ath10k_peer_cleanup(struct ath10k *ar, u32 vdev_id)
 static void ath10k_peer_cleanup_all(struct ath10k *ar)
 {
 	struct ath10k_peer *peer, *tmp;
+	int i;
 
 	lockdep_assert_held(&ar->conf_mutex);
 
@@ -836,6 +849,10 @@ static void ath10k_peer_cleanup_all(struct ath10k *ar)
 		list_del(&peer->list);
 		kfree(peer);
 	}
+
+	for (i = 0; i < ARRAY_SIZE(ar->peer_map); i++)
+		ar->peer_map[i] = NULL;
+
 	spin_unlock_bh(&ar->data_lock);
 
 	ar->num_peers = 0;