In the Linux kernel, following vulnerability has been resolved: net: dsa: qca8k: reset cpu port on MTU change It was discovered that Documentation lacks of a fundamental detail on how to correctly change MAX_FRAME_SIZE switch. In fact if is changed while on, the switch panics and cease send any packet. This cause mgmt ethernet system not receive packet (the slow fallback still works) and makes device reachable. To recover from this switch is required. To handle this, turn off ports before changing the MAX_FRAME_SIZE again after value applied.