[PATCH] : net : hso : unregister_netdev only if it has been registered

[PATCH] : net : hso : unregister_netdev only if it has been registered

[Yavuz, Tuba]

     
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.


Reported-by: Tuba Yavuz <tuba@ece.ufl.edu>
Signed-off-by: Tuba Yavuz <tuba@ece.ufl.edu>
---


--- drivers/net/usb/hso.c.orig	2019-01-27 14:45:58.232683119 -0500
+++ drivers/net/usb/hso.c	2019-01-27 14:47:43.592683629 -0500
@@ -2377,7 +2377,7 @@ 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 */​

Re: [PATCH] : net : hso : unregister_netdev only if it has been registered

[Greg KH]

On Sun, Jan 27, 2019 at 08:14:33PM +0000, Yavuz, Tuba wrote:
>      
> 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.
> 
> 
> Reported-by: Tuba Yavuz <tuba@ece.ufl.edu>
> Signed-off-by: Tuba Yavuz <tuba@ece.ufl.edu>

No need for a reported-by if you wrote the patch and sign off on it.

> ---
> 
> 
> --- drivers/net/usb/hso.c.orig	2019-01-27 14:45:58.232683119 -0500
> +++ drivers/net/usb/hso.c	2019-01-27 14:47:43.592683629 -0500

Your patches need to be one more level deep.  Please see the
documentatino for how to do this, git should also create this
automatically correctly for you.

thanks,

greg k-h