[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, 6 insertions, 0 deletions

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index fd1d52f0970..c1f1367cad4 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1403,6 +1403,9 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
         int origlen;
         __u16 len_hops;
 
+        if (dev->nd_net != &init_net)
+                goto freeit;
+
         /* Don't mangle buffer if shared */
         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
                 goto out;
@@ -1488,6 +1491,9 @@ freeit:
 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
                      struct packet_type *pt, struct net_device *orig_dev)
 {
+        if (dev->nd_net != &init_net)
+                goto freeit;
+
         /* Expand any short form frames */
         if (skb_mac_header(skb)[2] == 1) {
                 struct ddpehdr *ddp;