[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/ax25/ax25_in.c b/net/ax25/ax25_in.c
index 0ddaff0df217..3b7d1720c2ee 100644
--- a/net/ax25/ax25_in.c
+++ b/net/ax25/ax25_in.c
@@ -451,6 +451,11 @@ int ax25_kiss_rcv(struct sk_buff *skb, struct net_device *dev,
         skb->sk = NULL;         /* Initially we don't know who it's for */
         skb->destructor = NULL; /* Who initializes this, dammit?! */
 
+        if (dev->nd_net != &init_net) {
+                kfree_skb(skb);
+                return 0;
+        }
+
         if ((*skb->data & 0x0F) != 0) {
                 kfree_skb(skb); /* Not a KISS data frame */
                 return 0;