Commit 40b9d1ab authored by Mahesh Bandewar's avatar Mahesh Bandewar Committed by David S. Miller
Browse files

ipvlan: hold lower dev to avoid possible use-after-free 



Recently syzkaller discovered the issue of disappearing lower
device (NETDEV_UNREGISTER) while the virtual device (like
macvlan) is still having it as a lower device. So it's just
a matter of time similar discovery will be made for IPvlan
device setup. So fixing it preemptively. Also while at it,
add a refcount tracker.

Fixes: 2ad7bf36 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: default avatarMahesh Bandewar <maheshb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8207f253

drivers/net/ipvlan/ipvlan.h

+1 −0
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ struct ipvl_port { 
	struct sk_buff_head	backlog;

	int			count;

	struct ida		ida;

	netdevice_tracker	dev_tracker;

};



struct ipvl_skb_cb {

drivers/net/ipvlan/ipvlan_main.c

+2 −0
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ static int ipvlan_port_create(struct net_device *dev) 
	if (err)

		goto err;



	netdev_hold(dev, &port->dev_tracker, GFP_KERNEL);

	return 0;



err:
@@ -95,6 +96,7 @@ static void ipvlan_port_destroy(struct net_device *dev) 
	struct ipvl_port *port = ipvlan_port_get_rtnl(dev);

	struct sk_buff *skb;



	netdev_put(dev, &port->dev_tracker);

	if (port->mode == IPVLAN_MODE_L3S)

		ipvlan_l3s_unregister(port);

	netdev_rx_handler_unregister(dev);