Commit 56b1b7c6 authored May 13, 2020 by Xin Long Committed by Steffen Klassert May 14, 2020

esp6: calculate transport_header correctly when sel.family != AF_INET6



In esp6_init_state() for beet mode when x->sel.family != AF_INET6:

  x->props.header_len = sizeof(struct ip_esp_hdr) +
     crypto_aead_ivsize(aead) + IPV4_BEET_PHMAXLEN +
     (sizeof(struct ipv6hdr) - sizeof(struct iphdr))

In xfrm6_beet_gso_segment() skb->transport_header is supposed to move
to the end of the ph header for IPPROTO_BEETPH, so if x->sel.family !=
AF_INET6 and it's IPPROTO_BEETPH, it should do:

   skb->transport_header -=
      (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
   skb->transport_header += ph->hdrlen * 8;

And IPV4_BEET_PHMAXLEN is only reserved for PH header, so if
x->sel.family != AF_INET6 and it's not IPPROTO_BEETPH, it should do:

   skb->transport_header -=
      (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
   skb->transport_header -= IPV4_BEET_PHMAXLEN;

Thanks Sabrina for looking deep into this issue.

Fixes: 7f9e40eb ("esp6: add gso_segment for esp6 beet mode")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

parent c95c5f58

net/ipv6/esp6_offload.c

+15 −12

Original line number	Diff line number	Diff line
		@@ -175,24 +175,27 @@ static struct sk_buff xfrm6_beet_gso_segment(struct xfrm_state x,

		skb->transport_header += x->props.header_len;

		if (x->sel.family != AF_INET6) {
		skb->transport_header -=
		(sizeof(struct ipv6hdr) - sizeof(struct iphdr));

		if (proto == IPPROTO_BEETPH) {
		struct ip_beet_phdr ph = (struct ip_beet_phdr )skb->data;
		struct ip_beet_phdr *ph =
		(struct ip_beet_phdr *)skb->data;

		skb->transport_header += ph->hdrlen * 8;
		proto = ph->nexthdr;
		} else {
		skb->transport_header -= IPV4_BEET_PHMAXLEN;
		}

		if (x->sel.family == AF_INET6) {
		if (proto == IPPROTO_TCP)
		skb_shinfo(skb)->gso_type \|= SKB_GSO_TCPV6;
		} else {
		__be16 frag;

		skb->transport_header +=
		ipv6_skip_exthdr(skb, 0, &proto, &frag);
		} else {
		skb->transport_header -=
		(sizeof(struct ipv6hdr) - sizeof(struct iphdr));

		if (proto == IPPROTO_TCP)
		skb_shinfo(skb)->gso_type \|= SKB_GSO_TCPV6;
		}

		__skb_pull(skb, skb_transport_offset(skb));

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