diff --git a/net/can/isotp.c b/net/can/isotp.c
index b01662d2f2cd..ea1e227b8e54 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -196,7 +196,7 @@ static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
 	nskb->dev = dev;
 	can_skb_set_owner(nskb, sk);
 	ncf = (struct canfd_frame *)nskb->data;
-	skb_put(nskb, so->ll.mtu);
+	skb_put_zero(nskb, so->ll.mtu);
 
 	/* create & send flow control reply */
 	ncf->can_id = so->txid;
@@ -779,7 +779,7 @@ isotp_tx_burst:
 		can_skb_prv(skb)->skbcnt = 0;
 
 		cf = (struct canfd_frame *)skb->data;
-		skb_put(skb, so->ll.mtu);
+		skb_put_zero(skb, so->ll.mtu);
 
 		/* create consecutive frame */
 		isotp_fill_dataframe(cf, so, ae, 0);
@@ -887,7 +887,7 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 	so->tx.idx = 0;
 
 	cf = (struct canfd_frame *)skb->data;
-	skb_put(skb, so->ll.mtu);
+	skb_put_zero(skb, so->ll.mtu);
 
 	/* take care of a potential SF_DL ESC offset for TX_DL > 8 */
 	off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;