Some drivers, such as vxlan and wireguard, use the skb's dst in order to determine things like PMTU. They therefore loose functionality when flow offloading is enabled. So, we ensure the skb has it before xmit'ing it in the offloading path. Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- net/netfilter/nf_flow_table_ip.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 82451b7..15ed913 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -220,7 +220,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, enum flow_offload_tuple_dir dir; struct flow_offload *flow; struct net_device *outdev; - const struct rtable *rt; + struct rtable *rt; unsigned int thoff; struct iphdr *iph; __be32 nexthop; @@ -241,7 +241,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, dir = tuplehash->tuple.dir; flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]); - rt = (const struct rtable *)flow->tuplehash[dir].tuple.dst_cache; + rt = (struct rtable *)flow->tuplehash[dir].tuple.dst_cache; if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)) && (ip_hdr(skb)->frag_off & htons(IP_DF)) != 0) @@ -264,6 +264,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, skb->dev = outdev; nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr); + skb_dst_set_noref(skb, &rt->dst); neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb); return NF_STOLEN; @@ -480,6 +481,7 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, skb->dev = outdev; nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6); + skb_dst_set_noref(skb, &rt->dst); neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb); return NF_STOLEN;
