--- zzzz-none-000/linux-2.6.39.4/drivers/net/usb/cdc_ether.c	2011-08-03 19:43:28.000000000 +0000
+++ puma6-arm-6490-729/linux-2.6.39.4/drivers/net/usb/cdc_ether.c	2021-11-10 13:23:10.000000000 +0000
@@ -127,7 +127,10 @@
 
 	memset(info, 0, sizeof *info);
 	info->control = intf;
-	while (len > 3) {
+
+	/* == 20180119 AVM/WKR cdc parse security ported from cdc_ncm driver ==*/
+	while ((len > 0) && (buf[0] > 2) && (buf[0] <= len)) {
+
 		if (buf [1] != USB_DT_CS_INTERFACE)
 			goto next_desc;
 
@@ -164,7 +167,11 @@
 						"ACM capabilities %02x, "
 						"not really RNDIS?\n",
 						acm->bmCapabilities);
+
+/* 20160715 AVM/WK: Fix from AVM-Kernel 2.6.32 for buggy ZTE rndis modems, ignore buggy descriptor */
+#if 0
 					goto bad_desc;
+#endif
 				}
 			}
 			break;
@@ -326,6 +333,22 @@
 		usb_driver_release_interface(driver, info->data);
 		return -ENODEV;
 	}
+
+	/* Some devices don't initialise properly. In particular
+	 * the packet filter is not reset. There are devices that
+	 * don't do reset all the way. So the packet filter should
+	 * be set to a sane initial value.
+	 */
+	usb_control_msg(dev->udev,
+			usb_sndctrlpipe(dev->udev, 0),
+			USB_CDC_SET_ETHERNET_PACKET_FILTER,
+			USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+			USB_CDC_PACKET_TYPE_ALL_MULTICAST | USB_CDC_PACKET_TYPE_DIRECTED | USB_CDC_PACKET_TYPE_BROADCAST,
+			intf->cur_altsetting->desc.bInterfaceNumber,
+			NULL,
+			0,
+			USB_CTRL_SET_TIMEOUT
+		);
 	return 0;
 
 bad_desc: