kvm: module verification failed: signature and/or required key missing – tainting kernel

I’m using Ubuntu 14.04 LTS and kernel version 3.13.11.4.
I’m trying to load patched KVM modules kvm and kvm-intel and I’m getting the following errors

kvm: module verification failed: signature and/or required key missing - tainting kernel
and kvm: module has bad taint, not creating trace events.

The source used is the same source that created the image that I am currently running.
I’ve check the symbols and made sure to the error isn’t cause by not including EXPORT_SYMBOL_GPL() in the patched files where I exported functions.

I’ve also seen some stuff about different kernel versions causing this error but I built the kernel that I’m booted in with the same source that I used to create the patched kvm modules.
Everything compile without an warning. Any help is appreciated!

Answer

It seems like the vendor of your system has enabled kernel module signature verification on your kernel which means it won’t load any module that the vendor hasn’t signed. In other words, your patched module isn’t signed (properly) and the kernel will refuse to load it.

The point of this is supposed to prevent malware and rootkits from loading malicious kernel modules.

I suggest you contact your vendor. There may be an option somewhere on your platform to disable signature checking. Otherwise, your vendor may be able to sign the module for you. You might even have the key and the details of the signature verification algorithm and can sign it yourself.

Without knowing what platform you’re running on, it’s hard to give more specific suggestions.