From ea0371f7879987cff70e21d808e3e9fea624c051 Mon Sep 17 00:00:00 2001 From: Peter Oskolkov Date: Mon, 4 Mar 2019 16:27:08 -0800 Subject: [PATCH] net: fix GSO in bpf_lwt_push_ip_encap GSO needs inner headers and inner protocol set properly to work. skb->inner_mac_header: skb_reset_inner_headers() assigns the current mac header value to inner_mac_header; but it is not set at the point, so we need to call skb_reset_inner_mac_header, otherwise gre_gso_segment fails: it does int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); ... if (unlikely(!pskb_may_pull(skb, tnl_hlen))) ... skb->inner_protocol should also be correctly set. Fixes: ca78801a81e0 ("bpf: handle GSO in bpf_lwt_push_encap") Signed-off-by: Peter Oskolkov Reviewed-by: David Ahern Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- net/core/lwt_bpf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c index cf2f8897ca19..126d31ff5ee3 100644 --- a/net/core/lwt_bpf.c +++ b/net/core/lwt_bpf.c @@ -625,6 +625,8 @@ int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress) /* push the encap headers and fix pointers */ skb_reset_inner_headers(skb); + skb_reset_inner_mac_header(skb); /* mac header is not yet set */ + skb_set_inner_protocol(skb, skb->protocol); skb->encapsulation = 1; skb_push(skb, len); if (ingress)