Re: [PATCH 2/3] usb: musb-new: Limit check array index before use

[Mattijs Korpershoek <mkorpershoek@kernel.org>]

Hi Andrew,

Thank you for the patch.

On Tue, Sep 30, 2025 at 16:52, Andrew Goodbody <andrew.goodbody@linaro.org> wrote:

> epnum is used as an index into an array. The limit check for this index
> should be performed before using it to access an element in the array to
> prevent possible bounds overrun.
>
> This issue was found by Smatch.
>
> Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>

Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org>

> ---
>  drivers/usb/musb-new/musb_gadget_ep0.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/musb-new/musb_gadget_ep0.c b/drivers/usb/musb-new/musb_gadget_ep0.c
> index ea65326ab6264492ea668ddd047b360965a5ad19..25b1de6e58f9e2028e9b93a600d532ae0f5efcc1 100644
> --- a/drivers/usb/musb-new/musb_gadget_ep0.c
> +++ b/drivers/usb/musb-new/musb_gadget_ep0.c
> @@ -96,6 +96,9 @@ static int service_tx_status_request(
>  		if (!epnum) {
>  			result[0] = 0;
>  			break;
> +		} else if (epnum >= MUSB_C_NUM_EPS) {
> +			handled = -EINVAL;
> +			break;
>  		}
>  
>  		is_in = epnum & USB_DIR_IN;
> @@ -107,7 +110,7 @@ static int service_tx_status_request(
>  		}
>  		regs = musb->endpoints[epnum].regs;
>  
> -		if (epnum >= MUSB_C_NUM_EPS || !ep->desc) {
> +		if (!ep->desc) {
>  			handled = -EINVAL;
>  			break;
>  		}
>
> -- 
> 2.47.3