net: fix proc_fs init handling in af_packet and tls

proc_fs was used, in af_packet, without a surrounding #ifdef,
although there is no hard dependency on proc_fs.
That caused the initialization of the af_packet module to fail
when CONFIG_PROC_FS=n.

Specifically, proc_create_net() was used in af_packet.c,
and when it fails, packet_net_init() returns -ENOMEM.
It will always fail when the kernel is compiled without proc_fs,
because, proc_create_net() for example always returns NULL.

The calling order that starts in af_packet.c is as follows:
packet_init()
register_pernet_subsys()
register_pernet_operations()
__register_pernet_operations()
ops_init()
ops->init() (packet_net_ops.init=packet_net_init())
proc_create_net()

It worked in the past because register_pernet_subsys()'s return value
wasn't checked before this Commit 36096f2f4fa0 ("packet: Fix error path in
packet_init.").
It always returned an error, but was not checked before, so everything
was working even when CONFIG_PROC_FS=n.

The fix here is simply to add the necessary #ifdef.

This also fixes a similar error in tls_proc.c, that was found by Jakub
Kicinski.

Fixes: d26b698dd3cd ("net/tls: add skeleton of MIB statistics")
Fixes: 36096f2f4fa0 ("packet: Fix error path in packet_init")
Signed-off-by: Yonatan Linik <yonatanlinik@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/tls/tls_proc.c b/net/tls/tls_proc.c
index 3a5dd1e07233..feeceb0e4cb4 100644
--- a/net/tls/tls_proc.c
+++ b/net/tls/tls_proc.c
@@ -37,9 +37,12 @@ static int tls_statistics_seq_show(struct seq_file *seq, void *v)
 
 int __net_init tls_proc_init(struct net *net)
 {
+#ifdef CONFIG_PROC_FS
 	if (!proc_create_net_single("tls_stat", 0444, net->proc_net,
 				    tls_statistics_seq_show, NULL))
 		return -ENOMEM;
+#endif /* CONFIG_PROC_FS */
+
 	return 0;
 }