Re: [PATCH 5.15.y] can: gs_usb: gs_usb_receive_bulk_callback(): fix URB memory leak

[Greg KH <greg@kroah.com>]

On Tue, Jan 20, 2026 at 02:21:56PM +0100, Marc Kleine-Budde wrote:
> In gs_can_open(), the URBs for USB-in transfers are allocated, added to the
> parent->rx_submitted anchor and submitted. In the complete callback
> gs_usb_receive_bulk_callback(), the URB is processed and resubmitted. In
> gs_can_close() the URBs are freed by calling
> usb_kill_anchored_urbs(parent->rx_submitted).
> 
> However, this does not take into account that the USB framework unanchors
> the URB before the complete function is called. This means that once an
> in-URB has been completed, it is no longer anchored and is ultimately not
> released in gs_can_close().
> 
> Fix the memory leak by anchoring the URB in the
> gs_usb_receive_bulk_callback() to the parent->rx_submitted anchor.
> 
> Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
> Cc: stable@vger.kernel.org
> Link: https://patch.msgid.link/20260105-gs_usb-fix-memory-leak-v2-1-cc6ed6438034@pengutronix.de
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> (cherry picked from commit 7352e1d5932a0e777e39fa4b619801191f57e603)
> ---
>  drivers/net/can/usb/gs_usb.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
> index ffa2a4d92d01..e36745fd2d3b 100644
> --- a/drivers/net/can/usb/gs_usb.c
> +++ b/drivers/net/can/usb/gs_usb.c
> @@ -402,6 +402,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
>  			  usbcan
>  			  );
>  
> +	usb_anchor_urb(urb, &parent->rx_submitted);
> +

Breaks the build :(