This is why:
"""[…] The IETF draft for CIPSO is under a non-free license. The nvidia and riva drivers contain obfuscated source code. The other files contain executable code as static data, without any source for it. […]""" (https://groups.google.com/g/linux.debian.kernel/c/Pqw8klO72FE)
Got curious (while waiting for the compiler) after seeing a LKML discussion regarding the Appletalk FW license in the #LinuxKernel: https://lore.kernel.org/all/6100798b-ab1d-262a-fd5b-435d6dfc4a53@redhat.com/
