Re: [PATCH] usb: cdns3: Fix potential dereference of NULL pointer

[Greg KH]

On Wed, May 18, 2022 at 01:12:50AM -0700, Yongzhi Liu wrote:
> The return value of cdns3_gadget_ep_alloc_request()
> needs to be checked to avoid use of NULL pointer
> in case of an allocation failure.
> 
> Fixes: 7733f6c32e36f ("usb: cdns3: Add Cadence USB3 DRD Driver")
> 
> Signed-off-by: Yongzhi Liu <lyz_cs@xxxxxxxxxx>

Again, no blank line and use the full width for your text.

> ---
>  drivers/usb/cdns3/cdns3-gadget.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index 5d8c982..7be328e 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -2568,6 +2568,10 @@ static int cdns3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
>  		struct cdns3_request *priv_req;
>  
>  		zlp_request = cdns3_gadget_ep_alloc_request(ep, GFP_ATOMIC);
> +		if (!zlp_request) {
> +			ret = -ENOMEM;
> +			goto err;
> +		}

How did you test this that the if the allocation fails this will clean
up properly?

thanks,

greg k-h