tcp: fix mark propagation with fwmark_reflect enabled

commit bf99b4ded5f8a4767dbb9d180626f06c51f9881f upstream.

Otherwise, RST packets generated by the TCP stack for non-existing
sockets always have mark 0.
The mark from the original packet is assigned to the netns_ipv4/6
socket used to send the response so that it can get copied into the
response skb when the socket sends it.

Fixes: e110861f8609 ("net: add a sysctl to reflect the fwmark on replies")
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Pau Espin Pedrol <pau.espin@tessares.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index e5ee107a0575..5200c676fc72 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -837,6 +837,7 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
         if (!IS_ERR(dst)) {
                 skb_dst_set(buff, dst);
+                ctl_sk->sk_mark = fl6.flowi6_mark;
                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
                 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
                 if (rst)