ath10k: add some sanity checks to peer_map_event() functions

Smatch complains that since "ev->peer_id" comes from skb->data that
means we can't trust it and have to do a bounds check on it to prevent
an array overflow.

Fixes: 6942726f ('ath10k: add fast peer_map lookup')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

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

@@ -190,6 +190,13 @@ void ath10k_peer_map_event(struct ath10k_htt *htt,
 	struct ath10k *ar = htt->ar;
 	struct ath10k_peer *peer;
 
+	if (ev->peer_id >= ATH10K_MAX_NUM_PEER_IDS) {
+		ath10k_warn(ar,
+			    "received htt peer map event with idx out of bounds: %hu\n",
+			    ev->peer_id);
+		return;
+	}
+
 	spin_lock_bh(&ar->data_lock);
 	peer = ath10k_peer_find(ar, ev->vdev_id, ev->addr);
 	if (!peer) {
@@ -218,6 +225,13 @@ void ath10k_peer_unmap_event(struct ath10k_htt *htt,
 	struct ath10k *ar = htt->ar;
 	struct ath10k_peer *peer;
 
+	if (ev->peer_id >= ATH10K_MAX_NUM_PEER_IDS) {
+		ath10k_warn(ar,
+			    "received htt peer unmap event with idx out of bounds: %hu\n",
+			    ev->peer_id);
+		return;
+	}
+
 	spin_lock_bh(&ar->data_lock);
 	peer = ath10k_peer_find_by_id(ar, ev->peer_id);
 	if (!peer) {