[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/tipc/eth_media.c b/net/tipc/eth_media.c
index 711ca4b1f051..d2ed23704189 100644
--- a/net/tipc/eth_media.c
+++ b/net/tipc/eth_media.c
@@ -38,6 +38,7 @@
 #include <net/tipc/tipc_bearer.h>
 #include <net/tipc/tipc_msg.h>
 #include <linux/netdevice.h>
+#include <net/net_namespace.h>
 
 #define MAX_ETH_BEARERS         2
 #define ETH_LINK_PRIORITY       TIPC_DEF_LINK_PRI
@@ -100,6 +101,11 @@ static int recv_msg(struct sk_buff *buf, struct net_device *dev,
         struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
         u32 size;
 
+        if (dev->nd_net != &init_net) {
+                kfree_skb(buf);
+                return 0;
+        }
+
         if (likely(eb_ptr->bearer)) {
                 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
                         size = msg_size((struct tipc_msg *)buf->data);