Re: [PATCH 4/5] usb: usbnet: Add validation of dev->maxpacket to usbnet

[Oliver Neukum <oliver@neukum.org>]

Am Mittwoch, 15. Februar 2012, 15:47:40 schrieb Toby Gray:
> Several parts of usbnet rely on dev->maxpacket not being set to 0 to
> prevent division by zero errors.
> 
> This adds validation of the dev->maxpacket value being non-zero before
> treating the device probe as successful.
> 
> Signed-off-by: Toby Gray <toby.gray@realvnc.com>
> ---
>  drivers/net/usb/usbnet.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
> index 4ccd316..1491c90 100644
> --- a/drivers/net/usb/usbnet.c
> +++ b/drivers/net/usb/usbnet.c
> @@ -1427,6 +1427,10 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
>  		dev->rx_urb_size = dev->hard_mtu;
>  	if (!dev->maxpacket)
>  		dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
> +	if (!dev->maxpacket) {
> +		status = -ENODEV;
> +		goto out3;

Hm. I am sceptical. If this happens a subdriver is buggy. We should
not hide that. I am afraid I have to reject this patch.

	Regards
		Oliver