From 00c870e276c64bd0c7fde0f90831f2a4ec0b6c9f Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 8 Feb 2019 16:39:52 +0100 Subject: [PATCH] netfilter: nat: fix spurious connection timeouts Sander Eikelenboom bisected a NAT related regression down to the l4proto->manip_pkt indirection removal. I forgot that ICMP(v6) errors (e.g. PKTTOOBIG) can be set as related to the existing conntrack entry. Therefore, when passing the skb to nf_nat_ipv4/6_manip_pkt(), that ended up calling the wrong l4 manip function, as tuple->dst.protonum is the original flows l4 protocol (TCP, UDP, etc). Set the dst protocol field to ICMP(v6), we already have a private copy of the tuple due to the inversion of src/dst. Reported-by: Sander Eikelenboom Tested-by: Sander Eikelenboom Fixes: 7204bc8f0c7fc ("netfilter: nat: remove l4proto->manip_pkt") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/nf_nat_l3proto_ipv4.c | 1 + net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 1 + 2 files changed, 2 insertions(+) diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c index 2687db015b6f1..fa2ba7c500e41 100644 --- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c @@ -215,6 +215,7 @@ int nf_nat_icmp_reply_translation(struct sk_buff *skb, /* Change outer to look like the reply to an incoming packet */ nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); + target.dst.protonum = IPPROTO_ICMP; if (!nf_nat_ipv4_manip_pkt(skb, 0, &target, manip)) return 0; diff --git a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c index 23022447eb497..7a41ee3c11b4d 100644 --- a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c @@ -226,6 +226,7 @@ int nf_nat_icmpv6_reply_translation(struct sk_buff *skb, } nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); + target.dst.protonum = IPPROTO_ICMPV6; if (!nf_nat_ipv6_manip_pkt(skb, 0, &target, manip)) return 0; -- 2.39.5