Re: [PATCH] usbip: Fix vep_free_request() null pointer checks on input args

From: Greg KH
Date: Sat Jan 19 2019 - 03:17:20 EST


On Fri, Jan 18, 2019 at 02:29:30PM -0700, Shuah Khan wrote:
> From: Shuah Khan <shuah@xxxxxxxxxx>
>
> Fix vep_free_request() to return when usb_ep and usb_request are null
> instead of calling WARN_ON.
>
> Signed-off-by: Shuah Khan <shuah@xxxxxxxxxx>
> ---
> drivers/usb/usbip/vudc_dev.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/usbip/vudc_dev.c b/drivers/usb/usbip/vudc_dev.c
> index 1634d8698e15..bfc8218e3fb6 100644
> --- a/drivers/usb/usbip/vudc_dev.c
> +++ b/drivers/usb/usbip/vudc_dev.c
> @@ -297,7 +297,7 @@ static void vep_free_request(struct usb_ep *_ep, struct usb_request *_req)
> {
> struct vrequest *req;
>
> - if (WARN_ON(!_ep || !_req))
> + if (!_ep || !_req)

It's impossible for _ep to be NULL in this callback (see
usb_ep_free_request() for where this is called from to prove that), so I
don't think you need to check that. It's almost impossible for _req to
be NULL, so you might as well leave that check in.

thanks,

greg k-h