Re: [PATCH 0/6] MODSIGN: Kernel module signing

On Wed, 14 Feb 2007 23:13:45 EST, Dave Jones said:

One argument in its favour is aparently Red Hat isn't the only vendor
with something like this.  I've not investigated it, but I hear rumours
that suse has something similar.  Having everyone using the same code
would be a win for obvious reasons.

Another argument in its favor is that it actually allows the kernel to
implement *real* checking of module licenses and trumps all the proposals
to deal with MODULE_LICENSE("GPL\0Haha!").  A vendor (or user) that wants
to be *sure* that only *really really* GPL modules are loaded can simply
refuse to load unsigned modules - and then refuse to sign a module until
after they had themselves visited the source's website, verified that the
source code was available under GPL, and so on.

Remember - the GPL is about the availability of the source.  And at modprobe
time, the source isn't available.  So you're left with two options:

1) Trust the binary to not lie to you about its license.
2) Ask a trusted 3rd party (usually, the person/distro that built the kernel)
whether they've verified the claim that it's really GPL.