The SSL/TLS handshake code in LanLinkProvider is normally invoked in parallel, so that multiple incoming messages can be read at once. However, this logic causes an unusual crash in Android 8.1's native openssl library.
Sample logcat of crash is available at https://paste.kde.org/ptolqcpya
This patch mitigates the issue by making the addLink function in that class synchronized. I recommend future work to determine whether there are any other thread-safety concerns in the handshake code.