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macvlan: fix a race on port dismantle and possible skb leaks

We need to cancel the work queue after rcu grace period,
otherwise it can be rescheduled by incoming packets.

We need to purge queue if some skbs are still in it.

We can use __skb_queue_head_init() variant in
macvlan_process_broadcast()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 412ca1550c ("macvlan: Move broadcasts into a work queue")
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Eric Dumazet 2014-10-22 19:43:46 -07:00 committed by David S. Miller
parent 349ce993ac
commit fe0ca7328d
1 changed files with 8 additions and 2 deletions

View File

@ -272,7 +272,7 @@ static void macvlan_process_broadcast(struct work_struct *w)
struct sk_buff *skb;
struct sk_buff_head list;
skb_queue_head_init(&list);
__skb_queue_head_init(&list);
spin_lock_bh(&port->bc_queue.lock);
skb_queue_splice_tail_init(&port->bc_queue, &list);
@ -1082,9 +1082,15 @@ static void macvlan_port_destroy(struct net_device *dev)
{
struct macvlan_port *port = macvlan_port_get_rtnl(dev);
cancel_work_sync(&port->bc_work);
dev->priv_flags &= ~IFF_MACVLAN_PORT;
netdev_rx_handler_unregister(dev);
/* After this point, no packet can schedule bc_work anymore,
* but we need to cancel it and purge left skbs if any.
*/
cancel_work_sync(&port->bc_work);
__skb_queue_purge(&port->bc_queue);
kfree_rcu(port, rcu);
}