Message ID | 20180913144306.9077-1-toke@toke.dk |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
Series | [net,v2] gso_segment: Reset skb->mac_len after modifying network header | expand |
From: Toke Høiland-Jørgensen <toke@toke.dk> Date: Thu, 13 Sep 2018 16:43:07 +0200 > When splitting a GSO segment that consists of encapsulated packets, the > skb->mac_len of the segments can end up being set wrong, causing packet > drops in particular when using act_mirred and ifb interfaces in > combination with a qdisc that splits GSO packets. > > This happens because at the time skb_segment() is called, network_header > will point to the inner header, throwing off the calculation in > skb_reset_mac_len(). The network_header is subsequently adjust by the > outer IP gso_segment handlers, but they don't set the mac_len. > > Fix this by adding skb_reset_mac_len() calls to both the IPv4 and IPv6 > gso_segment handlers, after they modify the network_header. > > Many thanks to Eric Dumazet for his help in identifying the cause of > the bug. > > Acked-by: Dave Taht <dave.taht@gmail.com> > Reviewed-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> > --- > v2: > - Properly credit Eric for his help > - Add review and ack tags Applied and queued up for -stable, thanks.
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 20fda8fb8ffd..1fbe2f815474 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1377,6 +1377,7 @@ struct sk_buff *inet_gso_segment(struct sk_buff *skb, if (encap) skb_reset_inner_headers(skb); skb->network_header = (u8 *)iph - skb->head; + skb_reset_mac_len(skb); } while ((skb = skb->next)); out: diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index 37ff4805b20c..c7e495f12011 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -115,6 +115,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, payload_len = skb->len - nhoff - sizeof(*ipv6h); ipv6h->payload_len = htons(payload_len); skb->network_header = (u8 *)ipv6h - skb->head; + skb_reset_mac_len(skb); if (udpfrag) { int err = ip6_find_1stfragopt(skb, &prevhdr);