| Message ID | 20170420125512.GA9113@gondor.apana.org.au |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Herbert Xu <herbert@gondor.apana.org.au> Date: Thu, 20 Apr 2017 20:55:12 +0800 > 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 <Joe.Ghalam@dell.com> > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Applied and queued up for -stable, thanks Herbert.
From: David Miller <davem@davemloft.net> Sent: Tuesday, April 25, 2017 7:42 AM To: herbert@gondor.apana.org.au Cc: Ghalam, Joe; Wichmann, Clifford; netdev@vger.kernel.org Subject: Re: macvlan: Fix device ref leak when purging bc_queue > Applied and queued up for -stable, thanks Herbert. Herbert and David, Glad to report that we had 10 iterations of the test that was showing 100% failure with Herbert's changes, and we have not seen any failures. The fix is good. Thanks for the help. Joe
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 9261722..b34eaaa 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -1139,6 +1139,7 @@ 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); @@ -1147,7 +1148,15 @@ 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(port); }
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 <Joe.Ghalam@dell.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>