diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 6e2923b30150..3b2a4a9d79d6 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -460,6 +460,13 @@ static int iso_connect_cis(struct sock *sk)
 		goto unlock;
 	}
 
+	/* Check if there are available buffers for output/TX. */
+	if (iso_pi(sk)->qos.ucast.out.sdu && !hci_iso_count(hdev) &&
+	    (hdev->iso_pkts && !hdev->iso_cnt)) {
+		err = -ENOBUFS;
+		goto unlock;
+	}
+
 	/* Just bind if DEFER_SETUP has been set */
 	if (test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) {
 		hcon = hci_bind_cis(hdev, &iso_pi(sk)->dst,