This applies to kernel 4.10 and newer.
See 8db4c5be88
The above commit added to kernel 4.10 added new dependency
for building the NETFILTER_XT_MATCH_SOCKET (xt_socket.ko)
module. The NF_SOCKET_IPVx options (both of them) need to
be enabled in order to build the NETFILTER_XT_MATCH_SOCKET
module. Without the change the module is not built.
Signed-off-by: Oldřich Jedlička <oldium.pro@gmail.com>
66e875a070