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 close 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
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
Changes in v2:
- correct "Fixes" tag
- add stable@v.k.o on Cc
- Link to v1: https://patch.msgid.link/20251225-gs_usb-fix-memory-leak-v1-1-a7b09e70d01d@pengutronix.de
---
 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 a0233e550a5a..d093babbc320 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -751,6 +751,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 			  hf, parent->hf_size_rx,
 			  gs_usb_receive_bulk_callback, parent);
 
+	usb_anchor_urb(urb, &parent->rx_submitted);
+
 	rc = usb_submit_urb(urb, GFP_ATOMIC);
 
 	/* USB failure take down all interfaces */

---
base-commit: 1806d210e5a8f431ad4711766ae4a333d407d972
change-id: 20251225-gs_usb-fix-memory-leak-062c24898cc9

Best regards,
--  
Marc Kleine-Budde <mkl@pengutronix.de>

On 05.01.2026 13:35:54, 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 close function is called. This means that
                               ^^^^^
                               complete

I've fixed it in my tree.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

On 05.01.2026 13:35:54, 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 close 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
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

applied to linux-can

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |