[PATCH -stable,4.14 11/11] netfilter: nf_tables: fix register ordering

[Pablo Neira Ayuso <pablo@netfilter.org>]

From: Florian Westphal <fw@strlen.de>

[ d209df3e7f7002d9099fdb0f6df0f972b4386a63 ]

[ We hit the trace described in commit message with the
kselftest/nft_trans_stress.sh. This patch diverges from the upstream one
since kernel 4.14 does not have following symbols:
nft_chain_filter_init, nf_tables_flowtable_notifier ]

We must register nfnetlink ops last, as that exposes nf_tables to
userspace.  Without this, we could theoretically get nfnetlink request
before net->nft state has been initialized.

Fixes: 99633ab29b213 ("netfilter: nf_tables: complete net namespace support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[apanyaki: backport to v4.14-stable]
Signed-off-by: Andrew Paniakin <apanyaki@amazon.com>
---
 net/netfilter/nf_tables_api.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 345fa29f34b9..241a3032d0e6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6105,18 +6105,25 @@ static int __init nf_tables_module_init(void)
 		goto err1;
 	}
 
-	err = nf_tables_core_module_init();
+	err = register_pernet_subsys(&nf_tables_net_ops);
 	if (err < 0)
 		goto err2;
 
-	err = nfnetlink_subsys_register(&nf_tables_subsys);
+	err = nf_tables_core_module_init();
 	if (err < 0)
 		goto err3;
 
+	/* must be last */
+	err = nfnetlink_subsys_register(&nf_tables_subsys);
+	if (err < 0)
+		goto err4;
+
 	pr_info("nf_tables: (c) 2007-2009 Patrick McHardy <kaber@trash.net>\n");
-	return register_pernet_subsys(&nf_tables_net_ops);
-err3:
+	return err;
+err4:
 	nf_tables_core_module_exit();
+err3:
+	unregister_pernet_subsys(&nf_tables_net_ops);
 err2:
 	kfree(info);
 err1:
-- 
2.30.2