Denial of service via malformed IPv4 packet in github.com/insomniacslk/dhcp

In github.com/insomniacslk/dhcp/dhcpv4/nclient4, BroadcastRawUDPConn.ReadFrom does not validate that the IPv4 payload length is sufficient to hold a UDP header before calculating the DHCP payload length. A frame with an IPv4 total-length field specifying fewer than eight payload bytes results in a negative DHCP length, causing a panic in buf.Consume due to a negative slice bound.