Re: [PATCH] usb: dwc2: gadget: Move a variable assignment behind condition checks in dwc2_hsotg_handle_outdone()

[Minas Harutyunyan]

On 4/19/23 22:12, Markus Elfring wrote:
> Date: Wed, 19 Apr 2023 20:06:25 +0200
> 
> The address of a data structure member was determined before
> a corresponding null pointer check in the implementation of
> the function “dwc2_hsotg_handle_outdone”.
> 
> Thus avoid the risk for undefined behaviour by moving the assignment
> for the variable “req” behind some condition checks.
> 
> This issue was detected by using the Coccinelle software.
> 
> Fixes: 5b7d70c6dbf2db786395cbd21750a1a4ce222f84 ("USB: Gadget driver for Samsung HS/OtG block")
> Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>

Acked-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>

> ---
>   drivers/usb/dwc2/gadget.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index 8b15742d9e8a..cab04816dd6c 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -2389,7 +2389,7 @@ static void dwc2_hsotg_handle_outdone(struct dwc2_hsotg *hsotg, int epnum)
>   	u32 epsize = dwc2_readl(hsotg, DOEPTSIZ(epnum));
>   	struct dwc2_hsotg_ep *hs_ep = hsotg->eps_out[epnum];
>   	struct dwc2_hsotg_req *hs_req = hs_ep->req;
> -	struct usb_request *req = &hs_req->req;
> +	struct usb_request *req;
>   	unsigned int size_left = DXEPTSIZ_XFERSIZE_GET(epsize);
>   	int result = 0;
> 
> @@ -2408,6 +2408,8 @@ static void dwc2_hsotg_handle_outdone(struct dwc2_hsotg *hsotg, int epnum)
>   	if (using_desc_dma(hsotg))
>   		size_left = dwc2_gadget_get_xfersize_ddma(hs_ep);
> 
> +	req = &hs_req->req;
> +
>   	if (using_dma(hsotg)) {
>   		unsigned int size_done;
> 
> --
> 2.40.0
>