static int proc_pident_readdir(struct file *filp,
		void *dirent, filldir_t filldir,
		const struct pid_entry *ents, unsigned int nents)
{
	int i;
	struct dentry *dentry = filp->f_path.dentry;
	struct inode *inode = dentry->d_inode;
	struct task_struct *task = get_proc_task(inode);
	const struct pid_entry *p, *last;
	ino_t ino;
	int ret;

	ret = -ENOENT;
	if (!task)
		goto out_no_task;

	ret = 0;
	i = filp->f_pos;
	switch (i) {
	case 0:
		ino = inode->i_ino;
		if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
			goto out;
		i++;
		filp->f_pos++;
		/* fall through */
	case 1:
		ino = parent_ino(dentry);
		if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
			goto out;
		i++;
		filp->f_pos++;
		/* fall through */
	default:
		i -= 2;
		if (i >= nents) {
			ret = 1;
			goto out;
		}
		p = ents + i;
		last = &ents[nents - 1];
		while (p <= last) {
			if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
				goto out;
			filp->f_pos++;
			p++;
		}
	}

	ret = 1;
out:
	put_task_struct(task);
out_no_task:
	return ret;
}

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