netfilter: cthelper: add missing attribute validation for cthelper

stable inclusion
from linux-4.19.111
commit 5b425d389ed2627aa04739a076b9da9a9adaad9e

--------------------------------

commit c049b345 upstream.

Add missing attribute validation for cthelper
to the netlink policy.

Fixes: 12f7a505 ("netfilter: add user-space connection tracking helper infrastructure")
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NLi Aichun <liaichun@huawei.com>
Reviewed-by: Nguodeqing <geffrey.guo@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/netfilter/nfnetlink_cthelper.c

@@ -744,6 +744,8 @@ static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
 	[NFCTH_NAME] = { .type = NLA_NUL_STRING,
 			 .len = NF_CT_HELPER_NAME_LEN-1 },
 	[NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
+	[NFCTH_PRIV_DATA_LEN] = { .type = NLA_U32, },
+	[NFCTH_STATUS] = { .type = NLA_U32, },
 };
 
 static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {