static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg)
{
	u32 __user *uregs = (u32 __user *)arg;
	u32 regs[8];
	int cpu = iminor(file->f_path.dentry->d_inode);
	int err;

	switch (ioc) {
	case X86_IOC_RDMSR_REGS:
		if (!(file->f_mode & FMODE_READ)) {
			err = -EBADF;
			break;
		}
		if (copy_from_user(&regs, uregs, sizeof regs)) {
			err = -EFAULT;
			break;
		}
		err = rdmsr_safe_regs_on_cpu(cpu, regs);
		if (err)
			break;
		if (copy_to_user(uregs, &regs, sizeof regs))
			err = -EFAULT;
		break;

	case X86_IOC_WRMSR_REGS:
		if (!(file->f_mode & FMODE_WRITE)) {
			err = -EBADF;
			break;
		}
		if (copy_from_user(&regs, uregs, sizeof regs)) {
			err = -EFAULT;
			break;
		}
		err = wrmsr_safe_regs_on_cpu(cpu, regs);
		if (err)
			break;
		if (copy_to_user(uregs, &regs, sizeof regs))
			err = -EFAULT;
		break;

	default:
		err = -ENOTTY;
		break;
	}

	return err;
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.