ipvlan: fix various issues in ipvlan_process_multicast()

1) netif_rx() / dev_forward_skb() should not be called from process
context.

2) ipvlan_count_rx() should be called with preemption disabled.

3) We should check if ipvlan->dev is up before feeding packets
to netif_rx()

4) We need to prevent device from disappearing if some packets
are in the multicast backlog.

5) One kfree_skb() should be a consume_skb() eventually

Fixes: ba35f8588f47 ("ipvlan: Defer multicast / broadcast processing to
a work-queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 693ec5b66222..8b0f99300cbc 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -135,6 +135,7 @@ err:
 static void ipvlan_port_destroy(struct net_device *dev)
 {
         struct ipvl_port *port = ipvlan_port_get_rtnl(dev);
+        struct sk_buff *skb;
 
         dev->priv_flags &= ~IFF_IPVLAN_MASTER;
         if (port->mode == IPVLAN_MODE_L3S) {
@@ -144,7 +145,11 @@ static void ipvlan_port_destroy(struct net_device *dev)
         }
         netdev_rx_handler_unregister(dev);
         cancel_work_sync(&port->wq);
-        __skb_queue_purge(&port->backlog);
+        while ((skb = __skb_dequeue(&port->backlog)) != NULL) {
+                if (skb->dev)
+                        dev_put(skb->dev);
+                kfree_skb(skb);
+        }
         kfree(port);
 }