--- drivers/net/pppol2tp.c

+++ drivers/net/pppol2tp.c

@@ -1178,7 +1178,8 @@ static int pppol2tp_xmit(struct ppp_chan

/* Calculate UDP checksum if configured to do so */

if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT)

skb->ip_summed = CHECKSUM_NONE;

- else if (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM)) {

+ else if ((skb_dst(skb) && skb_dst(skb)->dev) &&

+ (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) {

skb->ip_summed = CHECKSUM_COMPLETE;

csum = skb_checksum(skb, 0, udp_len, 0);

uh->check = csum_tcpudp_magic(inet->saddr, inet->daddr,