Re: [PATCH] usb: cdns2: fix a null pointer dereference in cdns2_gadget_ep_queue()

[Greg KH]

On Wed, Dec 24, 2025 at 05:38:45PM +0800, Haoxiang Li wrote:
> If cdns2_gadget_ep_alloc_request() fails, a null pointer dereference
> occurs. Add a check to prevent it.
> 
> Fixes: 3eb1f1efe204 ("usb: cdns2: Add main part of Cadence USBHS driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Haoxiang Li <lihaoxiang@xxxxxxxxxxxxxxxx>
> ---
>  drivers/usb/gadget/udc/cdns2/cdns2-gadget.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
> index 9b53daf76583..c5b9dae743d8 100644
> --- a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
> +++ b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
> @@ -1725,6 +1725,8 @@ static int cdns2_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
>  		struct cdns2_request *preq;
>  
>  		zlp_request = cdns2_gadget_ep_alloc_request(ep, GFP_ATOMIC);
> +		if (!zlp_request)
> +			return -ENOMEM;

As stated before, you need to document the tool that you use to find
these types of things.

And how was this tested?

thanks,

greg k-h