xfrm: add net device refcount tracker to struct xfrm_state_offload

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Link: https://lore.kernel.org/r/20211209154451.4184050-1-eric.dumazet@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/xfrm.h

@@ -128,6 +128,7 @@ struct xfrm_state_walk {
 
 struct xfrm_state_offload {
 	struct net_device	*dev;
+	netdevice_tracker	dev_tracker;
 	struct net_device	*real_dev;
 	unsigned long		offload_handle;
 	unsigned int		num_exthdrs;
@@ -1913,7 +1914,7 @@ static inline void xfrm_dev_state_free(struct xfrm_state *x)
 		if (dev->xfrmdev_ops->xdo_dev_state_free)
 			dev->xfrmdev_ops->xdo_dev_state_free(x);
 		xso->dev = NULL;
-		dev_put(dev);
+		dev_put_track(dev, &xso->dev_tracker);
 	}
 }
 #else

net/xfrm/xfrm_device.c

@@ -259,6 +259,7 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 	}
 
 	xso->dev = dev;
+	netdev_tracker_alloc(dev, &xso->dev_tracker, GFP_ATOMIC);
 	xso->real_dev = dev;
 	xso->num_exthdrs = 1;
 	xso->flags = xuo->flags;
@@ -269,7 +270,7 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 		xso->flags = 0;
 		xso->dev = NULL;
 		xso->real_dev = NULL;
-		dev_put(dev);
+		dev_put_track(dev, &xso->dev_tracker);
 
 		if (err != -EOPNOTSUPP)
 			return err;