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

Message ID 20221201191134.12404-1-szymon.heidrich@gmail.com
State Superseded
Headers show
Series [v2] usb: gadget: uvc: Prevent buffer overflow in setup handler | expand

Commit Message

Szymon Heidrich Dec. 1, 2022, 7:11 p.m. UTC
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@gmail.com>
---
V1 -> V2: Corrected commit message and changed ?: in favor of min_t

 drivers/usb/gadget/function/f_uvc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Daniel Scally Dec. 6, 2022, 11:33 a.m. UTC | #1
Hi Szymon

On 01/12/2022 19:11, Szymon Heidrich wrote:
> Setup function uvc_function_setuppermits 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@gmail.com>


Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>


This probably needs to be tagged with:


Fixes: cdda479f15cd ("USB gadget: video class function driver")

> ---
> V1 -> V2: Corrected commit message and changed ?: in favor of min_t
>
>   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);
>   	}
>   }
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Patch

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);
 	}
 }