From 15df03c661cb362366ecfc3a21820cb934f3e4ca Mon Sep 17 00:00:00 2001 From: Eli Cooper Date: Mon, 21 Jan 2019 18:45:27 +0800 Subject: [PATCH] netfilter: ipv6: Don't preserve original oif for loopback address Commit 508b09046c0f ("netfilter: ipv6: Preserve link scope traffic original oif") made ip6_route_me_harder() keep the original oif for link-local and multicast packets. However, it also affected packets for the loopback address because it used rt6_need_strict(). REDIRECT rules in the OUTPUT chain rewrite the destination to loopback address; thus its oif should not be preserved. This commit fixes the bug that redirected local packets are being dropped. Actually the packet was not exactly dropped; Instead it was sent out to the original oif rather than lo. When a packet with daddr ::1 is sent to the router, it is effectively dropped. Fixes: 508b09046c0f ("netfilter: ipv6: Preserve link scope traffic original oif") Signed-off-by: Eli Cooper Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index 8b075f0bc351..6d0b1f3e927b 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -23,9 +23,11 @@ int ip6_route_me_harder(struct net *net, struct sk_buff *skb) struct sock *sk = sk_to_full_sk(skb->sk); unsigned int hh_len; struct dst_entry *dst; + int strict = (ipv6_addr_type(&iph->daddr) & + (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); struct flowi6 fl6 = { .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if : - rt6_need_strict(&iph->daddr) ? skb_dst(skb)->dev->ifindex : 0, + strict ? skb_dst(skb)->dev->ifindex : 0, .flowi6_mark = skb->mark, .flowi6_uid = sock_net_uid(net, sk), .daddr = iph->daddr,