int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode)
{
	struct ecryptfs_inode_info *inode_info;
	int count, rc = 0;

	inode_info = ecryptfs_inode_to_private(inode);
	mutex_lock(&inode_info->lower_file_mutex);
	count = atomic_inc_return(&inode_info->lower_file_count);
	if (WARN_ON_ONCE(count < 1))
		rc = -EINVAL;
	else if (count == 1) {
		rc = ecryptfs_init_lower_file(dentry,
					      &inode_info->lower_file);
		if (rc)
			atomic_set(&inode_info->lower_file_count, 0);
	}
	mutex_unlock(&inode_info->lower_file_mutex);
	return rc;
}

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