diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index c4ba845f7e5d..860c086011b7 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -2681,6 +2681,14 @@ static int mgmt_hci_cmd_sync(struct sock *sk, struct hci_dev *hdev,
 		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_HCI_CMD_SYNC,
 				       MGMT_STATUS_INVALID_PARAMS);
 
+	/* The HCI command header carries the parameter length in a u8, a
+	 * larger value would be truncated there while the parameters are
+	 * still appended to the frame in full.
+	 */
+	if (le16_to_cpu(cp->params_len) > U8_MAX)
+		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_HCI_CMD_SYNC,
+				       MGMT_STATUS_INVALID_PARAMS);
+
 	hci_dev_lock(hdev);
 	cmd = mgmt_pending_new(sk, MGMT_OP_HCI_CMD_SYNC, hdev, data, len);
 	if (!cmd)