Thanks for guide. Applied patch as described, after du to 4.14 kernal and modules build OK.
root@sweep:/usr/src/virtualbox-5.2.0# patch -Np1 < virtualbox-modules-5.1.28-udp.patch
patching file vboxnetflt/linux/VBoxNetFlt-linux.c
Hunk #1 succeeded at 141 (offset 15 lines).
patching file vboxpci/linux/VBoxPci-linux.c
patch unexpectedly ends in middle of line
Hunk #1 succeeded at 353 with fuzz 2.
root@sweep:/usr/src/virtualbox-5.2.0#
root@sweep:/# dkms status
virtualbox, 5.2.0, 4.13.11-towo.1-siduction-amd64, x86_64: installed
virtualbox, 5.2.0, 4.14.0-towo.1-siduction-amd64, x86_64: installed
About to reboot and test vbox. Seems Ok, no error found in either using a bridged network or internal network in Vboxx.