This is a note to let you know that I've just added the patch titled
ipvlan: hold lower dev to avoid possible use-after-free
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipvlan-hold-lower-dev-to-avoid-possible-use-after-fr.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ccee9bc96eff59f1be118e10b85dce17a9303402
Author: Mahesh Bandewar <maheshb@xxxxxxxxxx>
Date: Tue Nov 15 17:19:14 2022 -0800
ipvlan: hold lower dev to avoid possible use-after-free
[ Upstream commit 40b9d1ab63f5c4f3cb69450044d07b45e5af72e1 ]
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: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: Mahesh Bandewar <maheshb@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h
index de94921cbef9..025e0c19ec25 100644
--- a/drivers/net/ipvlan/ipvlan.h
+++ b/drivers/net/ipvlan/ipvlan.h
@@ -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 {
diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 49ba8a50dfb1..9043bcd1b41d 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -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);
