GPL Source Code for FortiGate VM Appliances

Hi all,

the FortiGate VM appliances clearly contain binaries whose source code is licensed under the GPLv2, e.g., the Linux kernel. It is also evident that Fortinet made modifications to this source code, e.g., the rootfs decryption, and distributes these modified binaries. The GPL is pretty clear that the source code of those modifications must be made available.

After some reseach I was not able to find out where to obtain this source code. Does anybody know how to get it?

Best,

Zhu