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

Question

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 1

Instead of re-configuring the kernel, this error (module verification failed) could be resolved by just adding one line CONFIG_MODULE_SIG=n to the top of the Makefile for the module itself:

CONFIG_MODULE_SIG=n

# If KERNELRELEASE is defined, we've been invoked from the
# kernel build system and can use its language.
ifneq ($(KERNELRELEASE),)
    obj-m := hello.o

# Otherwise we were called directly from the command
# line; invoke the kernel build system.
else
    KERNELDIR ?= /lib/modules/$(shell uname -r)/build
    PWD := $(shell pwd)

default:
    $(MAKE) -C $(KERNELDIR) M=$(PWD) modules
endif