![James Morris](/assets/img/avatar_default.png)
Sparse fix: make aa_create_aafs static. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: John Johansen <john.johansen@canonical.com>
245 lines
5.6 KiB
C
245 lines
5.6 KiB
C
/*
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* AppArmor security module
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*
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* This file contains AppArmor /sys/kernel/security/apparmor interface functions
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*
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* Copyright (C) 1998-2008 Novell/SUSE
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* Copyright 2009-2010 Canonical Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*/
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#include <linux/security.h>
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#include <linux/vmalloc.h>
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <linux/uaccess.h>
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#include <linux/namei.h>
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#include "include/apparmor.h"
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#include "include/apparmorfs.h"
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#include "include/audit.h"
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#include "include/context.h"
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#include "include/policy.h"
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/**
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* aa_simple_write_to_buffer - common routine for getting policy from user
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* @op: operation doing the user buffer copy
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* @userbuf: user buffer to copy data from (NOT NULL)
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* @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
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* @copy_size: size of data to copy from user buffer
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* @pos: position write is at in the file (NOT NULL)
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*
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* Returns: kernel buffer containing copy of user buffer data or an
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* ERR_PTR on failure.
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*/
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static char *aa_simple_write_to_buffer(int op, const char __user *userbuf,
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size_t alloc_size, size_t copy_size,
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loff_t *pos)
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{
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char *data;
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BUG_ON(copy_size > alloc_size);
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if (*pos != 0)
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/* only writes from pos 0, that is complete writes */
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return ERR_PTR(-ESPIPE);
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/*
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* Don't allow profile load/replace/remove from profiles that don't
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* have CAP_MAC_ADMIN
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*/
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if (!aa_may_manage_policy(op))
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return ERR_PTR(-EACCES);
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/* freed by caller to simple_write_to_buffer */
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data = kvmalloc(alloc_size);
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if (data == NULL)
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return ERR_PTR(-ENOMEM);
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if (copy_from_user(data, userbuf, copy_size)) {
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kvfree(data);
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return ERR_PTR(-EFAULT);
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}
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return data;
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}
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/* .load file hook fn to load policy */
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static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
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loff_t *pos)
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{
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char *data;
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ssize_t error;
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data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos);
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error = PTR_ERR(data);
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if (!IS_ERR(data)) {
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error = aa_replace_profiles(data, size, PROF_ADD);
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kvfree(data);
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}
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return error;
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}
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static const struct file_operations aa_fs_profile_load = {
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.write = profile_load,
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.llseek = default_llseek,
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};
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/* .replace file hook fn to load and/or replace policy */
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static ssize_t profile_replace(struct file *f, const char __user *buf,
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size_t size, loff_t *pos)
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{
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char *data;
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ssize_t error;
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data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos);
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error = PTR_ERR(data);
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if (!IS_ERR(data)) {
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error = aa_replace_profiles(data, size, PROF_REPLACE);
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kvfree(data);
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}
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return error;
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}
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static const struct file_operations aa_fs_profile_replace = {
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.write = profile_replace,
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.llseek = default_llseek,
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};
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/* .remove file hook fn to remove loaded policy */
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static ssize_t profile_remove(struct file *f, const char __user *buf,
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size_t size, loff_t *pos)
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{
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char *data;
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ssize_t error;
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/*
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* aa_remove_profile needs a null terminated string so 1 extra
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* byte is allocated and the copied data is null terminated.
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*/
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data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos);
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error = PTR_ERR(data);
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if (!IS_ERR(data)) {
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data[size] = 0;
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error = aa_remove_profiles(data, size);
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kvfree(data);
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}
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return error;
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}
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static const struct file_operations aa_fs_profile_remove = {
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.write = profile_remove,
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.llseek = default_llseek,
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};
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/** Base file system setup **/
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static struct dentry *aa_fs_dentry __initdata;
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static void __init aafs_remove(const char *name)
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{
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struct dentry *dentry;
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dentry = lookup_one_len(name, aa_fs_dentry, strlen(name));
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if (!IS_ERR(dentry)) {
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securityfs_remove(dentry);
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dput(dentry);
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}
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}
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/**
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* aafs_create - create an entry in the apparmor filesystem
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* @name: name of the entry (NOT NULL)
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* @mask: file permission mask of the file
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* @fops: file operations for the file (NOT NULL)
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*
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* Used aafs_remove to remove entries created with this fn.
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*/
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static int __init aafs_create(const char *name, int mask,
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const struct file_operations *fops)
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{
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struct dentry *dentry;
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dentry = securityfs_create_file(name, S_IFREG | mask, aa_fs_dentry,
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NULL, fops);
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return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
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}
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/**
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* aa_destroy_aafs - cleanup and free aafs
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*
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* releases dentries allocated by aa_create_aafs
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*/
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void __init aa_destroy_aafs(void)
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{
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if (aa_fs_dentry) {
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aafs_remove(".remove");
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aafs_remove(".replace");
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aafs_remove(".load");
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securityfs_remove(aa_fs_dentry);
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aa_fs_dentry = NULL;
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}
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}
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/**
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* aa_create_aafs - create the apparmor security filesystem
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*
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* dentries created here are released by aa_destroy_aafs
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*
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* Returns: error on failure
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*/
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static int __init aa_create_aafs(void)
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{
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int error;
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if (!apparmor_initialized)
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return 0;
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if (aa_fs_dentry) {
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AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
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return -EEXIST;
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}
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aa_fs_dentry = securityfs_create_dir("apparmor", NULL);
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if (IS_ERR(aa_fs_dentry)) {
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error = PTR_ERR(aa_fs_dentry);
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aa_fs_dentry = NULL;
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goto error;
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}
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error = aafs_create(".load", 0640, &aa_fs_profile_load);
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if (error)
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goto error;
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error = aafs_create(".replace", 0640, &aa_fs_profile_replace);
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if (error)
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goto error;
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error = aafs_create(".remove", 0640, &aa_fs_profile_remove);
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if (error)
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goto error;
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/* TODO: add support for apparmorfs_null and apparmorfs_mnt */
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/* Report that AppArmor fs is enabled */
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aa_info_message("AppArmor Filesystem Enabled");
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return 0;
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error:
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aa_destroy_aafs();
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AA_ERROR("Error creating AppArmor securityfs\n");
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return error;
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}
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fs_initcall(aa_create_aafs);
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