From: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> commit d1e158e2d7a0a91110b206653f0e02376e809150 upstream. info is in network byte order, change it back to host byte order before use. In particular, the current code sets the MTU of the tunnel to a wrong (too big) value. Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Willy Tarreau <w@xxxxxx> --- net/ipv6/ip6_gre.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index ae88e17..529348e 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -419,7 +419,7 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt, if (code == ICMPV6_HDR_FIELD) teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data); - if (teli && teli == info - 2) { + if (teli && teli == be32_to_cpu(info) - 2) { tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; if (tel->encap_limit == 0) { net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n", @@ -431,7 +431,7 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt, } break; case ICMPV6_PKT_TOOBIG: - mtu = info - offset; + mtu = be32_to_cpu(info) - offset; if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; t->dev->mtu = mtu; -- 2.8.0.rc2.1.gbe9624a