[NET]: Make packet reception network namespace safe

This patch modifies every packet receive function
registered with dev_add_pack() to drop packets if they
are not from the initial network namespace.

This should ensure that the various network stacks do
not receive packets in a anything but the initial network
namespace until the code has been converted and is ready
for them.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 30a5cb1b203e..7d18cac3f110 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -61,6 +61,11 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
         u32             pkt_len;
         struct inet6_dev *idev;
 
+        if (dev->nd_net != &init_net) {
+                kfree_skb(skb);
+                return 0;
+        }
+
         if (skb->pkt_type == PACKET_OTHERHOST) {
                 kfree_skb(skb);
                 return 0;