long kvm_arch_vcpu_ioctl(struct file *filp,
			 unsigned int ioctl, unsigned long arg)
{
	struct kvm_vcpu *vcpu = filp->private_data;
	void __user *argp = (void __user *)arg;

	switch (ioctl) {
	case KVM_ARM_VCPU_INIT: {
		struct kvm_vcpu_init init;

		if (copy_from_user(&init, argp, sizeof(init)))
			return -EFAULT;

		return kvm_vcpu_set_target(vcpu, &init);

	}
	case KVM_SET_ONE_REG:
	case KVM_GET_ONE_REG: {
		struct kvm_one_reg reg;

		if (unlikely(!kvm_vcpu_initialized(vcpu)))
			return -ENOEXEC;

		if (copy_from_user(&reg, argp, sizeof(reg)))
			return -EFAULT;
		if (ioctl == KVM_SET_ONE_REG)
			return kvm_arm_set_reg(vcpu, &reg);
		else
			return kvm_arm_get_reg(vcpu, &reg);
	}
	case KVM_GET_REG_LIST: {
		struct kvm_reg_list __user *user_list = argp;
		struct kvm_reg_list reg_list;
		unsigned n;

		if (unlikely(!kvm_vcpu_initialized(vcpu)))
			return -ENOEXEC;

		if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
			return -EFAULT;
		n = reg_list.n;
		reg_list.n = kvm_arm_num_regs(vcpu);
		if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
			return -EFAULT;
		if (n < reg_list.n)
			return -E2BIG;
		return kvm_arm_copy_reg_indices(vcpu, user_list->reg);
	}
	default:
		return -EINVAL;
	}
}
Weaknesses in this category are related to improper management of system resources.