diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 82e3629617c8..fd6cd47a6c5a 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -5553,6 +5553,19 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn,
 	BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
 	       scid, mtu, mps);
 
+	/* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
+	 * page 1059:
+	 *
+	 * Valid range: 0x0001-0x00ff
+	 *
+	 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
+	 */
+	if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
+		result = L2CAP_CR_BAD_PSM;
+		chan = NULL;
+		goto response;
+	}
+
 	/* Check if we have socket listening on psm */
 	pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
 					 &conn->hcon->dst, LE_LINK);