Hi Yu,
On Tue, 4 Jul 2023 16:25:50 -0700
Yu Hao <yhao016@xxxxxxx> wrote:
> The struct usb_ctrlrequest setup should be initialized in the function
> ep0_read_setup(mtu, &setup). However, inside that function,
> the variable count could be 0 and the struct usb_ctrlrequest setup
> is not initialized. But there is a read for setup.bRequestType.
>
> Signed-off-by: Yu Hao <yhao016@xxxxxxx>
> ---
> drivers/usb/mtu3/mtu3_gadget_ep0.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/mtu3/mtu3_gadget_ep0.c
> b/drivers/usb/mtu3/mtu3_gadget_ep0.c
> index e4fd1bb14a55..67034fa515d0 100644
> --- a/drivers/usb/mtu3/mtu3_gadget_ep0.c
> +++ b/drivers/usb/mtu3/mtu3_gadget_ep0.c
> @@ -638,7 +638,7 @@ static int ep0_handle_setup(struct mtu3 *mtu)
> __releases(mtu->lock)
> __acquires(mtu->lock)
> {
> - struct usb_ctrlrequest setup;
> + struct usb_ctrlrequest setup = {};
> struct mtu3_request *mreq;
> int handled = 0;
>
Looks strange to me because, if ep0_read_setup() cannot read the setup data
why don't we simply abort the operation ?
With setup = {}, the following test is true:
if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
handled = handle_standard_request(mtu, &setup);
handle_standard_request() is called and supposes an USB_REQ_GET_STATUS
(0x00) request:
case USB_REQ_GET_STATUS:
handled = ep0_get_status(mtu, setup);
break;
Then ep0_get_status() supposes USB_RECIP_DEVICE (0x00) and performs some
operation sending the data related to the GET_STATUS.
All of these are not correct as the setup data that triggered this sequence
was never received.
Aborting the operation if ep0_read_setup() cannot read the setup data seems
better to me.
Best regards,
Hervé
--
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
