From: Tobias Brunner Date: Tue, 24 Jun 2025 12:47:20 +0000 (+0200) Subject: xfrm: Set transport header to fix UDP GRO handling X-Git-Tag: v6.16~15^2^2~3 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3ac9e29211fa2df5539ba0d742c8fe9fe95fdc79;p=thirdparty%2Fkernel%2Flinux.git xfrm: Set transport header to fix UDP GRO handling The referenced commit replaced a call to __xfrm4|6_udp_encap_rcv() with a custom check for non-ESP markers. But what the called function also did was setting the transport header to the ESP header. The function that follows, esp4|6_gro_receive(), relies on that being set when it calls xfrm_parse_spi(). We have to set the full offset as the skb's head was not moved yet so adding just the UDP header length won't work. Fixes: e3fd05777685 ("xfrm: Fix UDP GRO handling for some corner cases") Signed-off-by: Tobias Brunner Signed-off-by: Steffen Klassert --- diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c index 0d31a8c108d4f..f28cfd88eaf59 100644 --- a/net/ipv4/xfrm4_input.c +++ b/net/ipv4/xfrm4_input.c @@ -202,6 +202,9 @@ struct sk_buff *xfrm4_gro_udp_encap_rcv(struct sock *sk, struct list_head *head, if (len <= sizeof(struct ip_esp_hdr) || udpdata32[0] == 0) goto out; + /* set the transport header to ESP */ + skb_set_transport_header(skb, offset); + NAPI_GRO_CB(skb)->proto = IPPROTO_UDP; pp = call_gro_receive(ops->callbacks.gro_receive, head, skb); diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c index 841c81abaaf4f..9005fc156a20e 100644 --- a/net/ipv6/xfrm6_input.c +++ b/net/ipv6/xfrm6_input.c @@ -202,6 +202,9 @@ struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head, if (len <= sizeof(struct ip_esp_hdr) || udpdata32[0] == 0) goto out; + /* set the transport header to ESP */ + skb_set_transport_header(skb, offset); + NAPI_GRO_CB(skb)->proto = IPPROTO_UDP; pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);