Subject: [PATCH] net: hso: do not unregister if not registered

From: "Yavuz, Tuba" <[email-masked]>
Date: Wed, 6 Feb 2019 00:40:31 +0000

On an error path inside the hso_create_net_device function of the hso
driver, hso_free_net_device gets called. This causes potentially a
negative reference count in the net device if register_netdev has not
been called yet as hso_free_net_device calls unregister_netdev
regardless. I think the driver should distinguish these cases and call
unregister_netdev only if register_netdev has been called.

Signed-off-by: Tuba Yavuz <[email-masked]>
---

--- linux-stable/drivers/net/usb/hso.c.orig     2019-01-27 14:45:58.232683119 -0500
+++ linux-stable/drivers/net/usb/hso.c  2019-02-05 17:54:17.056496019 -0500
@@ -2377,7 +2377,9 @@ static void hso_free_net_device(struct h
 
        remove_net_device(hso_net->parent);
 
-       if (hso_net->net)
+       if (hso_net->net &&
+           hso_net->net->reg_state == NETREG_REGISTERED)
                unregister_netdev(hso_net->net);
 
        /* start freeing */