OSV-2020-496 Stack-buffer-overflow in ot::Mle::Mle::HandleParentResponse

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=15382 Crash type: Stack-buffer-overflow READ Crash state: ot::Mle::Mle::HandleParentResponse ot::Mle::Mle::HandleUdpReceive ot::Ip6::Udp::HandleMessage...