diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 1a24c1d9dd8f..17ea2be8abee 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -156,10 +156,6 @@ struct gs_host_frame {
 #define GS_MAX_TX_URBS 10
 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
 #define GS_MAX_RX_URBS 30
-/* Maximum number of interfaces the driver supports per device.
- * Current hardware only supports 2 interfaces. The future may vary.
- */
-#define GS_MAX_INTF 2
 
 struct gs_tx_context {
 	struct gs_can *dev;
@@ -190,10 +186,11 @@ struct gs_can {
 
 /* usb interface struct */
 struct gs_usb {
-	struct gs_can *canch[GS_MAX_INTF];
 	struct usb_anchor rx_submitted;
 	struct usb_device *udev;
 	u8 active_channels;
+	u8 channel_cnt;
+	struct gs_can *canch[];
 };
 
 /* 'allocate' a tx context.
@@ -321,7 +318,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 	}
 
 	/* device reports out of range channel id */
-	if (hf->channel >= GS_MAX_INTF)
+	if (hf->channel >= usbcan->channel_cnt)
 		goto device_detach;
 
 	dev = usbcan->canch[hf->channel];
@@ -409,7 +406,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 	/* USB failure take down all interfaces */
 	if (rc == -ENODEV) {
  device_detach:
-		for (rc = 0; rc < GS_MAX_INTF; rc++) {
+		for (rc = 0; rc < usbcan->channel_cnt; rc++) {
 			if (usbcan->canch[rc])
 				netif_device_detach(usbcan->canch[rc]->netdev);
 		}
@@ -991,20 +988,22 @@ static int gs_usb_probe(struct usb_interface *intf,
 	icount = dconf->icount + 1;
 	dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 
-	if (icount > GS_MAX_INTF) {
+	if (icount > type_max(typeof(dev->channel_cnt))) {
 		dev_err(&intf->dev,
-			"Driver cannot handle more that %d CAN interfaces\n",
-			GS_MAX_INTF);
+			"Driver cannot handle more that %u CAN interfaces\n",
+			type_max(typeof(dev->channel_cnt)));
 		kfree(dconf);
 		return -EINVAL;
 	}
 
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	dev = kzalloc(struct_size(dev, canch, icount), GFP_KERNEL);
 	if (!dev) {
 		kfree(dconf);
 		return -ENOMEM;
 	}
 
+	dev->channel_cnt = icount;
+
 	init_usb_anchor(&dev->rx_submitted);
 
 	usb_set_intfdata(intf, dev);
@@ -1045,7 +1044,7 @@ static void gs_usb_disconnect(struct usb_interface *intf)
 		return;
 	}
 
-	for (i = 0; i < GS_MAX_INTF; i++)
+	for (i = 0; i < dev->channel_cnt; i++)
 		if (dev->canch[i])
 			gs_destroy_candev(dev->canch[i]);