Marker PDU reflection without rate-limiting or request-address validation: on-link amplification DoS

Summary

lacp_marker_input(:1911-1922) unconditionally converts MARKER_TYPE_INFO to RESPONSE and re-enqueues via lagg_enqueue. Unlike lacp_sm_tx(rate-limited by ppsratecheck :1829) marker responses have NO rate limiting. Slow-protocols multicast dst(:1901) delivers to every LAGG on segment -> N amplified responses per injected frame. No validation that mi_rq_system matches local. On-link attacker sustains bandwidth/CPU exhaustion.