tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced()

Make sure we use the correct address-family-specific function for
handling MTU reductions from within tcp_release_cb().

Previously AF_INET6 sockets were incorrectly always using the IPv6
code path when sometimes they were handling IPv4 traffic and thus had
an IPv4 dst.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Diagnosed-by: Willem de Bruijn <willemb@google.com>
Fixes: 563d34d057862 ("tcp: dont drop MTU reduction indications")
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index f2ce95502392..29964c3d363c 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1595,6 +1595,7 @@ static const struct inet_connection_sock_af_ops ipv6_specific = {
         .compat_setsockopt = compat_ipv6_setsockopt,
         .compat_getsockopt = compat_ipv6_getsockopt,
 #endif
+        .mtu_reduced       = tcp_v6_mtu_reduced,
 };
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -1625,6 +1626,7 @@ static const struct inet_connection_sock_af_ops ipv6_mapped = {
         .compat_setsockopt = compat_ipv6_setsockopt,
         .compat_getsockopt = compat_ipv6_getsockopt,
 #endif
+        .mtu_reduced       = tcp_v4_mtu_reduced,
 };
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -1864,7 +1866,6 @@ struct proto tcpv6_prot = {
         .sendpage               = tcp_sendpage,
         .backlog_rcv            = tcp_v6_do_rcv,
         .release_cb             = tcp_release_cb,
-        .mtu_reduced            = tcp_v6_mtu_reduced,
         .hash                   = tcp_v6_hash,
         .unhash                 = inet_unhash,
         .get_port               = inet_csk_get_port,