void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
	if (vcpu->arch.time_page) {
		kvm_release_page_dirty(vcpu->arch.time_page);
		vcpu->arch.time_page = NULL;
	}

	free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
	fx_free(vcpu);
	kvm_x86_ops->vcpu_free(vcpu);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.