Re: [PATCH v2] usb: gadget: uvc: Prevent buffer overflow in setup handler

[Greg Kroah-Hartman]

On Thu, Dec 01, 2022 at 04:45:46PM +0100, Szymon Heidrich wrote:
> Setup function uvc_function_setup permits control transfer
> requests with up to 64 bytes of payload (UVC_MAX_REQUEST_SIZE),
> data stage handler for OUT transfer uses memcpy to copy req->actual
> bytes to uvc_event->data.data array of size 60. This may result
> in an overflow of 4 bytes.
> 
> Signed-off-by: Szymon Heidrich <szymon.heidrich@xxxxxxxxx>
> ---
>  drivers/usb/gadget/function/f_uvc.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
> index 6e196e061..4419b7972 100644
> --- a/drivers/usb/gadget/function/f_uvc.c
> +++ b/drivers/usb/gadget/function/f_uvc.c
> @@ -216,8 +216,9 @@ uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
>  
>  		memset(&v4l2_event, 0, sizeof(v4l2_event));
>  		v4l2_event.type = UVC_EVENT_DATA;
> -		uvc_event->data.length = req->actual;
> -		memcpy(&uvc_event->data.data, req->buf, req->actual);
> +		uvc_event->data.length = min_t(unsigned int, req->actual,
> +			sizeof(uvc_event->data.data));
> +		memcpy(&uvc_event->data.data, req->buf, uvc_event->data.length);
>  		v4l2_event_queue(&uvc->vdev, &v4l2_event);
>  	}
>  }
> -- 
> 2.38.1
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
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