Re: [PATCH v2] usb: cdns3: change place of NULL check in cdns3_gadget_ep_enable()

[Greg Kroah-Hartman]

On Thu, Jul 28, 2022 at 07:30:14PM +0300, Andrey Strachuk wrote:
> If 'ep' is NULL, result of ep_to_cdns3_ep(ep) is invalid and
> priv_ep->cdns3_dev causes panic.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Signed-off-by: Andrey Strachuk <strochuk@xxxxxxxxx>
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> ---
>  drivers/usb/cdns3/cdns3-gadget.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

No information on what changed from v1 to v2 :(

> 
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index 5c15c48952a6..51de7457a3b8 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -2284,11 +2284,14 @@ static int cdns3_gadget_ep_enable(struct usb_ep *ep,
>  	int ret = 0;
>  	int val;
>  
> +	if (!ep)
> +		return -EINVAL;

How can ep ever be NULL at all?  Why does this need to be checked?

thanks,

greg k-h