diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 9f99af5b0b11e74b7718be8fa3300e01fc36a4dc..1a68b00e7980abcb272d60a62f07b05f2bd6dfe1 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -330,6 +330,9 @@ static void j1939_session_skb_drop_old(struct j1939_session *session)
 
 	if ((do_skcb->offset + do_skb->len) < offset_start) {
 		__skb_unlink(do_skb, &session->skb_queue);
+		/* drop ref taken in j1939_session_skb_queue() */
+		skb_unref(do_skb);
+
 		kfree_skb(do_skb);
 	}
 	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
@@ -349,20 +352,20 @@ void j1939_session_skb_queue(struct j1939_session *session,
 
 	skcb->flags |= J1939_ECU_LOCAL_SRC;
 
+	skb_get(skb);
 	skb_queue_tail(&session->skb_queue, skb);
 }
 
-static struct sk_buff *j1939_session_skb_find(struct j1939_session *session)
+static struct
+sk_buff *j1939_session_skb_get_by_offset(struct j1939_session *session,
+					 unsigned int offset_start)
 {
 	struct j1939_priv *priv = session->priv;
+	struct j1939_sk_buff_cb *do_skcb;
 	struct sk_buff *skb = NULL;
 	struct sk_buff *do_skb;
-	struct j1939_sk_buff_cb *do_skcb;
-	unsigned int offset_start;
 	unsigned long flags;
 
-	offset_start = session->pkt.dpo * 7;
-
 	spin_lock_irqsave(&session->skb_queue.lock, flags);
 	skb_queue_walk(&session->skb_queue, do_skb) {
 		do_skcb = j1939_skb_to_cb(do_skb);
@@ -372,6 +375,10 @@ static struct sk_buff *j1939_session_skb_find(struct j1939_session *session)
 			skb = do_skb;
 		}
 	}
+
+	if (skb)
+		skb_get(skb);
+
 	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
 
 	if (!skb)
@@ -382,6 +389,14 @@ static struct sk_buff *j1939_session_skb_find(struct j1939_session *session)
 	return skb;
 }
 
+static struct sk_buff *j1939_session_skb_get(struct j1939_session *session)
+{
+	unsigned int offset_start;
+
+	offset_start = session->pkt.dpo * 7;
+	return j1939_session_skb_get_by_offset(session, offset_start);
+}
+
 /* see if we are receiver
  * returns 0 for broadcasts, although we will receive them
  */
@@ -766,7 +781,7 @@ static int j1939_session_tx_dat(struct j1939_session *session)
 	int ret = 0;
 	u8 dat[8];
 
-	se_skb = j1939_session_skb_find(session);
+	se_skb = j1939_session_skb_get_by_offset(session, session->pkt.tx * 7);
 	if (!se_skb)
 		return -ENOBUFS;
 
@@ -787,6 +802,19 @@ static int j1939_session_tx_dat(struct j1939_session *session)
 		if (len > 7)
 			len = 7;
 
+		if (offset + len > se_skb->len) {
+			netdev_err_once(priv->ndev,
+					"%s: 0x%p: requested data outside of queued buffer: offset %i, len %i, pkt.tx: %i\n",
+					__func__, session, skcb->offset, se_skb->len , session->pkt.tx);
+			ret = -EOVERFLOW;
+			goto out_free;
+		}
+
+		if (!len) {
+			ret = -ENOBUFS;
+			break;
+		}
+
 		memcpy(&dat[1], &tpdat[offset], len);
 		ret = j1939_tp_tx_dat(session, dat, len + 1);
 		if (ret < 0) {
@@ -813,6 +841,12 @@ static int j1939_session_tx_dat(struct j1939_session *session)
 	if (pkt_done)
 		j1939_tp_set_rxtimeout(session, 250);
 
+ out_free:
+	if (ret)
+		kfree_skb(se_skb);
+	else
+		consume_skb(se_skb);
+
 	return ret;
 }
 
@@ -985,7 +1019,7 @@ static int j1939_xtp_txnext_receiver(struct j1939_session *session)
 static int j1939_simple_txnext(struct j1939_session *session)
 {
 	struct j1939_priv *priv = session->priv;
-	struct sk_buff *se_skb = j1939_session_skb_find(session);
+	struct sk_buff *se_skb = j1939_session_skb_get(session);
 	struct sk_buff *skb;
 	int ret;
 
@@ -993,8 +1027,10 @@ static int j1939_simple_txnext(struct j1939_session *session)
 		return 0;
 
 	skb = skb_clone(se_skb, GFP_ATOMIC);
-	if (!skb)
-		return -ENOMEM;
+	if (!skb) {
+		ret = -ENOMEM;
+		goto out_free;
+	}
 
 	can_skb_set_owner(skb, se_skb->sk);
 
@@ -1002,12 +1038,18 @@ static int j1939_simple_txnext(struct j1939_session *session)
 
 	ret = j1939_send_one(priv, skb);
 	if (ret)
-		return ret;
+		goto out_free;
 
 	j1939_sk_errqueue(session, J1939_ERRQUEUE_SCHED);
 	j1939_sk_queue_activate_next(session);
 
-	return 0;
+ out_free:
+	if (ret)
+		kfree_skb(se_skb);
+	else
+		consume_skb(se_skb);
+
+	return ret;
 }
 
 static bool j1939_session_deactivate_locked(struct j1939_session *session)
@@ -1120,6 +1162,9 @@ static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
 		 * cleanup including propagation of the error to user space.
 		 */
 		break;
+	case -EOVERFLOW:
+		j1939_session_cancel(session, J1939_XTP_ABORT_ECTS_TOO_BIG);
+		break;
 	case 0:
 		session->tx_retry = 0;
 		break;
@@ -1145,9 +1190,10 @@ static void j1939_session_completed(struct j1939_session *session)
 	struct sk_buff *skb;
 
 	if (!session->transmission) {
-		skb = j1939_session_skb_find(session);
+		skb = j1939_session_skb_get(session);
 		/* distribute among j1939 receivers */
 		j1939_sk_recv(session->priv, skb);
+		consume_skb(skb);
 	}
 
 	j1939_session_deactivate_activate_next(session);
@@ -1710,7 +1756,7 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
 {
 	struct j1939_priv *priv = session->priv;
 	struct j1939_sk_buff_cb *skcb;
-	struct sk_buff *se_skb;
+	struct sk_buff *se_skb = NULL;
 	const u8 *dat;
 	u8 *tpdat;
 	int offset;
@@ -1750,7 +1796,8 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
 			    __func__, session);
 		goto out_session_cancel;
 	}
-	se_skb = j1939_session_skb_find(session);
+
+	se_skb = j1939_session_skb_get_by_offset(session, packet * 7);
 	if (!se_skb) {
 		netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
 			    session);
@@ -1793,11 +1840,13 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
 		j1939_tp_set_rxtimeout(session, 250);
 	}
 	session->last_cmd = 0xff;
+	consume_skb(se_skb);
 	j1939_session_put(session);
 
 	return;
 
  out_session_cancel:
+	kfree_skb(se_skb);
 	j1939_session_timers_cancel(session);
 	j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
 	j1939_session_put(session);