static enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
{
	struct kvm_vcpu *vcpu;

	vcpu = container_of(timer, struct kvm_vcpu, arch.dec_timer);
	kvmppc_decrementer_func(vcpu);

	return HRTIMER_NORESTART;
}

The product dereferences a pointer that it expects to be valid but is NULL.