From 6bd1dd04eabf96e403b99ee0f86e5bbf6ebacf4a Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 20 Apr 2017 20:55:12 +0800 Subject: [PATCH] macvlan: Fix device ref leak when purging bc_queue commit f6478218e6edc2a587b8f132f66373baa7b2497c upstream. When a parent macvlan device is destroyed we end up purging its broadcast queue without dropping the device reference count on the packet source device. This causes the source device to linger. This patch drops that reference count. Fixes: 260916dfb48c ("macvlan: Fix potential use-after free for...") Reported-by: Joe Ghalam Signed-off-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/net/macvlan.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 8432521408a7..7ba1bfea2864 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -942,6 +942,7 @@ static int macvlan_port_create(struct net_device *dev) static void macvlan_port_destroy(struct net_device *dev) { struct macvlan_port *port = macvlan_port_get_rtnl(dev); + struct sk_buff *skb; dev->priv_flags &= ~IFF_MACVLAN_PORT; netdev_rx_handler_unregister(dev); @@ -950,7 +951,15 @@ static void macvlan_port_destroy(struct net_device *dev) * but we need to cancel it and purge left skbs if any. */ cancel_work_sync(&port->bc_work); - __skb_queue_purge(&port->bc_queue); + + while ((skb = __skb_dequeue(&port->bc_queue))) { + const struct macvlan_dev *src = MACVLAN_SKB_CB(skb)->src; + + if (src) + dev_put(src->dev); + + kfree_skb(skb); + } kfree_rcu(port, rcu); } -- 2.39.5