net: shy netns_ok check

Failure to pass netns_ok check is SILENT, except some MIB counter is
incremented somewhere.

And adding "netns_ok = 1" (after long head-scratching session) is
usually the last step in making some protocol netns-ready...

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 1 deletions

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 861978a4f1a8..cfb38ac9d698 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -209,9 +209,17 @@ static int ip_local_deliver_finish(struct sk_buff *skb)
 
                 hash = protocol & (MAX_INET_PROTOS - 1);
                 ipprot = rcu_dereference(inet_protos[hash]);
-                if (ipprot != NULL && (net == &init_net || ipprot->netns_ok)) {
+                if (ipprot != NULL) {
                         int ret;
 
+                        if (!net_eq(net, &init_net) && !ipprot->netns_ok) {
+                                if (net_ratelimit())
+                                        printk("%s: proto %d isn't netns-ready\n",
+                                                __func__, protocol);
+                                kfree_skb(skb);
+                                goto out;
+                        }
+
                         if (!ipprot->no_policy) {
                                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
                                         kfree_skb(skb);