Merge patch series "can: usb: fix URB memory leaks"

Marc Kleine-Budde <mkl@pengutronix.de> says:

An URB memory leak [1][2] was recently fixed in the gs_usb driver. The
driver did not take into account that completed URBs are no longer
anchored, causing them to be lost during ifdown. The memory leak was fixed
by re-anchoring the URBs in the URB completion callback.

Several USB CAN drivers are affected by the same error. Fix them
accordingly.

[1] https://lore.kernel.org/all/20260109135311.576033-3-mkl@pengutronix.de/
[2] https://lore.kernel.org/all/20260116-can_usb-fix-reanchor-v1-1-9d74e7289225@pengutronix.de/

Link: https://patch.msgid.link/20260116-can_usb-fix-memory-leak-v2-0-4b8cb2915571@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Author: marckleinebudde

drivers/net/can/usb/ems_usb.c

@@ -486,11 +486,17 @@ static void ems_usb_read_bulk_callback(struct urb *urb)
 			  urb->transfer_buffer, RX_BUFFER_SIZE,
 			  ems_usb_read_bulk_callback, dev);
 
+	usb_anchor_urb(urb, &dev->rx_submitted);
+
 	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (!retval)
+		return;
+
+	usb_unanchor_urb(urb);
 
 	if (retval == -ENODEV)
 		netif_device_detach(netdev);
-	else if (retval)
+	else
 		netdev_err(netdev,
 			   "failed resubmitting read bulk urb: %d\n", retval);
 }

drivers/net/can/usb/esd_usb.c

@@ -541,13 +541,20 @@ static void esd_usb_read_bulk_callback(struct urb *urb)
 			  urb->transfer_buffer, ESD_USB_RX_BUFFER_SIZE,
 			  esd_usb_read_bulk_callback, dev);
 
+	usb_anchor_urb(urb, &dev->rx_submitted);
+
 	err = usb_submit_urb(urb, GFP_ATOMIC);
+	if (!err)
+		return;
+
+	usb_unanchor_urb(urb);
+
 	if (err == -ENODEV) {
 		for (i = 0; i < dev->net_count; i++) {
 			if (dev->nets[i])
 				netif_device_detach(dev->nets[i]->netdev);
 		}
-	} else if (err) {
+	} else {
 		dev_err(dev->udev->dev.parent,
 			"failed resubmitting read bulk urb: %pe\n", ERR_PTR(err));
 	}

drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c

@@ -361,7 +361,14 @@ static void kvaser_usb_read_bulk_callback(struct urb *urb)
 			  urb->transfer_buffer, KVASER_USB_RX_BUFFER_SIZE,
 			  kvaser_usb_read_bulk_callback, dev);
 
+	usb_anchor_urb(urb, &dev->rx_submitted);
+
 	err = usb_submit_urb(urb, GFP_ATOMIC);
+	if (!err)
+		return;
+
+	usb_unanchor_urb(urb);
+
 	if (err == -ENODEV) {
 		for (i = 0; i < dev->nchannels; i++) {
 			struct kvaser_usb_net_priv *priv;
@@ -372,7 +379,7 @@ static void kvaser_usb_read_bulk_callback(struct urb *urb)
 
 			netif_device_detach(priv->netdev);
 		}
-	} else if (err) {
+	} else {
 		dev_err(&dev->intf->dev,
 			"Failed resubmitting read bulk urb: %d\n", err);
 	}

drivers/net/can/usb/mcba_usb.c

@@ -608,11 +608,17 @@ static void mcba_usb_read_bulk_callback(struct urb *urb)
 			  urb->transfer_buffer, MCBA_USB_RX_BUFF_SIZE,
 			  mcba_usb_read_bulk_callback, priv);
 
+	usb_anchor_urb(urb, &priv->rx_submitted);
+
 	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (!retval)
+		return;
+
+	usb_unanchor_urb(urb);
 
 	if (retval == -ENODEV)
 		netif_device_detach(netdev);
-	else if (retval)
+	else
 		netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
 			   retval);
 }

drivers/net/can/usb/usb_8dev.c

@@ -541,11 +541,17 @@ static void usb_8dev_read_bulk_callback(struct urb *urb)
 			  urb->transfer_buffer, RX_BUFFER_SIZE,
 			  usb_8dev_read_bulk_callback, priv);
 
+	usb_anchor_urb(urb, &priv->rx_submitted);
+
 	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (!retval)
+		return;
+
+	usb_unanchor_urb(urb);
 
 	if (retval == -ENODEV)
 		netif_device_detach(netdev);
-	else if (retval)
+	else
 		netdev_err(netdev,
 			"failed resubmitting read bulk urb: %d\n", retval);
 }