security/apparmor/apparmorfs.c - kernel/msm-4.9 - Gitiles

 /*
  * AppArmor security module
  *
  * This file contains AppArmor /sys/kernel/security/apparmor interface functions
  *
  * Copyright (C) 1998-2008 Novell/SUSE
  * Copyright 2009-2010 Canonical Ltd.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation, version 2 of the
  * License.
  */

 #include <linux/security.h>
 #include <linux/vmalloc.h>
 #include <linux/module.h>
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 #include <linux/namei.h>
 #include <linux/capability.h>

 #include "include/apparmor.h"
 #include "include/apparmorfs.h"
 #include "include/audit.h"
 #include "include/context.h"
 #include "include/policy.h"
 #include "include/resource.h"

 /**
  * aa_simple_write_to_buffer - common routine for getting policy from user
  * @op: operation doing the user buffer copy
  * @userbuf: user buffer to copy data from  (NOT NULL)
  * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
  * @copy_size: size of data to copy from user buffer
  * @pos: position write is at in the file (NOT NULL)
  *
  * Returns: kernel buffer containing copy of user buffer data or an
  *          ERR_PTR on failure.
  */
 static char *aa_simple_write_to_buffer(int op, const char __user *userbuf,
 				       size_t alloc_size, size_t copy_size,
 				       loff_t *pos)
 {
 	char *data;

 	BUG_ON(copy_size > alloc_size);

 	if (*pos != 0)
 		/* only writes from pos 0, that is complete writes */
 		return ERR_PTR(-ESPIPE);

 	/*
 	 * Don't allow profile load/replace/remove from profiles that don't
 	 * have CAP_MAC_ADMIN
 	 */
 	if (!aa_may_manage_policy(op))
 		return ERR_PTR(-EACCES);

 	/* freed by caller to simple_write_to_buffer */
 	data = kvmalloc(alloc_size);
 	if (data == NULL)
 		return ERR_PTR(-ENOMEM);

 	if (copy_from_user(data, userbuf, copy_size)) {
 		kvfree(data);
 		return ERR_PTR(-EFAULT);
 	}

 	return data;
 }


 /* .load file hook fn to load policy */
 static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
 			    loff_t *pos)
 {
 	char *data;
 	ssize_t error;

 	data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos);

 	error = PTR_ERR(data);
 	if (!IS_ERR(data)) {
 		error = aa_replace_profiles(data, size, PROF_ADD);
 		kvfree(data);
 	}

 	return error;
 }

 static const struct file_operations aa_fs_profile_load = {
 	.write = profile_load,
 	.llseek = default_llseek,
 };

 /* .replace file hook fn to load and/or replace policy */
 static ssize_t profile_replace(struct file *f, const char __user *buf,
 			       size_t size, loff_t *pos)
 {
 	char *data;
 	ssize_t error;

 	data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos);
 	error = PTR_ERR(data);
 	if (!IS_ERR(data)) {
 		error = aa_replace_profiles(data, size, PROF_REPLACE);
 		kvfree(data);
 	}

 	return error;
 }

 static const struct file_operations aa_fs_profile_replace = {
 	.write = profile_replace,
 	.llseek = default_llseek,
 };

 /* .remove file hook fn to remove loaded policy */
 static ssize_t profile_remove(struct file *f, const char __user *buf,
 			      size_t size, loff_t *pos)
 {
 	char *data;
 	ssize_t error;

 	/*
 	 * aa_remove_profile needs a null terminated string so 1 extra
 	 * byte is allocated and the copied data is null terminated.
 	 */
 	data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos);

 	error = PTR_ERR(data);
 	if (!IS_ERR(data)) {
 		data[size] = 0;
 		error = aa_remove_profiles(data, size);
 		kvfree(data);
 	}

 	return error;
 }

 static const struct file_operations aa_fs_profile_remove = {
 	.write = profile_remove,
 	.llseek = default_llseek,
 };

 static int aa_fs_seq_show(struct seq_file *seq, void *v)
 {
 	struct aa_fs_entry *fs_file = seq->private;

 	if (!fs_file)
 		return 0;

 	switch (fs_file->v_type) {
 	case AA_FS_TYPE_BOOLEAN:
 		seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
 		break;
 	case AA_FS_TYPE_STRING:
 		seq_printf(seq, "%s\n", fs_file->v.string);
 		break;
 	case AA_FS_TYPE_U64:
 		seq_printf(seq, "%#08lx\n", fs_file->v.u64);
 		break;
 	default:
 		/* Ignore unpritable entry types. */
 		break;
 	}

 	return 0;
 }

 static int aa_fs_seq_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, aa_fs_seq_show, inode->i_private);
 }

 const struct file_operations aa_fs_seq_file_ops = {
 	.owner		= THIS_MODULE,
 	.open		= aa_fs_seq_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 /** Base file system setup **/

 static struct aa_fs_entry aa_fs_entry_file[] = {
 	AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \
 				  "link lock"),
 	{ }
 };

 static struct aa_fs_entry aa_fs_entry_domain[] = {
 	AA_FS_FILE_BOOLEAN("change_hat",	1),
 	AA_FS_FILE_BOOLEAN("change_hatv",	1),
 	AA_FS_FILE_BOOLEAN("change_onexec",	1),
 	AA_FS_FILE_BOOLEAN("change_profile",	1),
 	{ }
 };

 static struct aa_fs_entry aa_fs_entry_features[] = {
 	AA_FS_DIR("domain",			aa_fs_entry_domain),
 	AA_FS_DIR("file",			aa_fs_entry_file),
 	AA_FS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
 	AA_FS_DIR("rlimit",			aa_fs_entry_rlimit),
 	{ }
 };

 static struct aa_fs_entry aa_fs_entry_apparmor[] = {
 	AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),
 	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
 	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
 	AA_FS_DIR("features", aa_fs_entry_features),
 	{ }
 };

 static struct aa_fs_entry aa_fs_entry =
 	AA_FS_DIR("apparmor", aa_fs_entry_apparmor);

 /**
  * aafs_create_file - create a file entry in the apparmor securityfs
  * @fs_file: aa_fs_entry to build an entry for (NOT NULL)
  * @parent: the parent dentry in the securityfs
  *
  * Use aafs_remove_file to remove entries created with this fn.
  */
 static int __init aafs_create_file(struct aa_fs_entry *fs_file,
 				   struct dentry *parent)
 {
 	int error = 0;

 	fs_file->dentry = securityfs_create_file(fs_file->name,
 						 S_IFREG | fs_file->mode,
 						 parent, fs_file,
 						 fs_file->file_ops);
 	if (IS_ERR(fs_file->dentry)) {
 		error = PTR_ERR(fs_file->dentry);
 		fs_file->dentry = NULL;
 	}
 	return error;
 }

 /**
  * aafs_create_dir - recursively create a directory entry in the securityfs
  * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
  * @parent: the parent dentry in the securityfs
  *
  * Use aafs_remove_dir to remove entries created with this fn.
  */
 static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
 				  struct dentry *parent)
 {
 	int error;
 	struct aa_fs_entry *fs_file;

 	fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
 	if (IS_ERR(fs_dir->dentry)) {
 		error = PTR_ERR(fs_dir->dentry);
 		fs_dir->dentry = NULL;
 		goto failed;
 	}

 	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
 		if (fs_file->v_type == AA_FS_TYPE_DIR)
 			error = aafs_create_dir(fs_file, fs_dir->dentry);
 		else
 			error = aafs_create_file(fs_file, fs_dir->dentry);
 		if (error)
 			goto failed;
 	}

 	return 0;

 failed:
 	return error;
 }

 /**
  * aafs_remove_file - drop a single file entry in the apparmor securityfs
  * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
  */
 static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
 {
 	if (!fs_file->dentry)
 		return;

 	securityfs_remove(fs_file->dentry);
 	fs_file->dentry = NULL;
 }

 /**
  * aafs_remove_dir - recursively drop a directory entry from the securityfs
  * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
  */
 static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
 {
 	struct aa_fs_entry *fs_file;

 	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
 		if (fs_file->v_type == AA_FS_TYPE_DIR)
 			aafs_remove_dir(fs_file);
 		else
 			aafs_remove_file(fs_file);
 	}

 	aafs_remove_file(fs_dir);
 }

 /**
  * aa_destroy_aafs - cleanup and free aafs
  *
  * releases dentries allocated by aa_create_aafs
  */
 void __init aa_destroy_aafs(void)
 {
 	aafs_remove_dir(&aa_fs_entry);
 }

 /**
  * aa_create_aafs - create the apparmor security filesystem
  *
  * dentries created here are released by aa_destroy_aafs
  *
  * Returns: error on failure
  */
 static int __init aa_create_aafs(void)
 {
 	int error;

 	if (!apparmor_initialized)
 		return 0;

 	if (aa_fs_entry.dentry) {
 		AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
 		return -EEXIST;
 	}

 	/* Populate fs tree. */
 	error = aafs_create_dir(&aa_fs_entry, NULL);
 	if (error)
 		goto error;

 	/* TODO: add support for apparmorfs_null and apparmorfs_mnt */

 	/* Report that AppArmor fs is enabled */
 	aa_info_message("AppArmor Filesystem Enabled");
 	return 0;

 error:
 	aa_destroy_aafs();
 	AA_ERROR("Error creating AppArmor securityfs\n");
 	return error;
 }

 fs_initcall(aa_create_aafs);
	/*
	* AppArmor security module
	*
	* This file contains AppArmor /sys/kernel/security/apparmor interface functions
	*
	* Copyright (C) 1998-2008 Novell/SUSE
	* Copyright 2009-2010 Canonical Ltd.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation, version 2 of the
	* License.
	*/

	#include <linux/security.h>
	#include <linux/vmalloc.h>
	#include <linux/module.h>
	#include <linux/seq_file.h>
	#include <linux/uaccess.h>
	#include <linux/namei.h>
	#include <linux/capability.h>

	#include "include/apparmor.h"
	#include "include/apparmorfs.h"
	#include "include/audit.h"
	#include "include/context.h"
	#include "include/policy.h"
	#include "include/resource.h"

	/**
	* aa_simple_write_to_buffer - common routine for getting policy from user
	* @op: operation doing the user buffer copy
	* @userbuf: user buffer to copy data from (NOT NULL)
	* @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
	* @copy_size: size of data to copy from user buffer
	* @pos: position write is at in the file (NOT NULL)
	*
	* Returns: kernel buffer containing copy of user buffer data or an
	* ERR_PTR on failure.
	*/
	static char aa_simple_write_to_buffer(int op, const char __user userbuf,
	size_t alloc_size, size_t copy_size,
	loff_t *pos)
	{
	char *data;

	BUG_ON(copy_size > alloc_size);

	if (*pos != 0)
	/* only writes from pos 0, that is complete writes */
	return ERR_PTR(-ESPIPE);

	/*
	* Don't allow profile load/replace/remove from profiles that don't
	* have CAP_MAC_ADMIN
	*/
	if (!aa_may_manage_policy(op))
	return ERR_PTR(-EACCES);

	/* freed by caller to simple_write_to_buffer */
	data = kvmalloc(alloc_size);
	if (data == NULL)
	return ERR_PTR(-ENOMEM);

	if (copy_from_user(data, userbuf, copy_size)) {
	kvfree(data);
	return ERR_PTR(-EFAULT);
	}

	return data;
	}


	/* .load file hook fn to load policy */
	static ssize_t profile_load(struct file f, const char __user buf, size_t size,
	loff_t *pos)
	{
	char *data;
	ssize_t error;

	data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos);

	error = PTR_ERR(data);
	if (!IS_ERR(data)) {
	error = aa_replace_profiles(data, size, PROF_ADD);
	kvfree(data);
	}

	return error;
	}

	static const struct file_operations aa_fs_profile_load = {
	.write = profile_load,
	.llseek = default_llseek,
	};

	/* .replace file hook fn to load and/or replace policy */
	static ssize_t profile_replace(struct file f, const char __user buf,
	size_t size, loff_t *pos)
	{
	char *data;
	ssize_t error;

	data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos);
	error = PTR_ERR(data);
	if (!IS_ERR(data)) {
	error = aa_replace_profiles(data, size, PROF_REPLACE);
	kvfree(data);
	}

	return error;
	}

	static const struct file_operations aa_fs_profile_replace = {
	.write = profile_replace,
	.llseek = default_llseek,
	};

	/* .remove file hook fn to remove loaded policy */
	static ssize_t profile_remove(struct file f, const char __user buf,
	size_t size, loff_t *pos)
	{
	char *data;
	ssize_t error;

	/*
	* aa_remove_profile needs a null terminated string so 1 extra
	* byte is allocated and the copied data is null terminated.
	*/
	data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos);

	error = PTR_ERR(data);
	if (!IS_ERR(data)) {
	data[size] = 0;
	error = aa_remove_profiles(data, size);
	kvfree(data);
	}

	return error;
	}

	static const struct file_operations aa_fs_profile_remove = {
	.write = profile_remove,
	.llseek = default_llseek,
	};

	static int aa_fs_seq_show(struct seq_file seq, void v)
	{
	struct aa_fs_entry *fs_file = seq->private;

	if (!fs_file)
	return 0;

	switch (fs_file->v_type) {
	case AA_FS_TYPE_BOOLEAN:
	seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
	break;
	case AA_FS_TYPE_STRING:
	seq_printf(seq, "%s\n", fs_file->v.string);
	break;
	case AA_FS_TYPE_U64:
	seq_printf(seq, "%#08lx\n", fs_file->v.u64);
	break;
	default:
	/* Ignore unpritable entry types. */
	break;
	}

	return 0;
	}

	static int aa_fs_seq_open(struct inode inode, struct file file)
	{
	return single_open(file, aa_fs_seq_show, inode->i_private);
	}

	const struct file_operations aa_fs_seq_file_ops = {
	.owner = THIS_MODULE,
	.open = aa_fs_seq_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	/ Base file system setup /

	static struct aa_fs_entry aa_fs_entry_file[] = {
	AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \
	"link lock"),
	{ }
	};

	static struct aa_fs_entry aa_fs_entry_domain[] = {
	AA_FS_FILE_BOOLEAN("change_hat", 1),
	AA_FS_FILE_BOOLEAN("change_hatv", 1),
	AA_FS_FILE_BOOLEAN("change_onexec", 1),
	AA_FS_FILE_BOOLEAN("change_profile", 1),
	{ }
	};

	static struct aa_fs_entry aa_fs_entry_features[] = {
	AA_FS_DIR("domain", aa_fs_entry_domain),
	AA_FS_DIR("file", aa_fs_entry_file),
	AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK),
	AA_FS_DIR("rlimit", aa_fs_entry_rlimit),
	{ }
	};

	static struct aa_fs_entry aa_fs_entry_apparmor[] = {
	AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),
	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
	AA_FS_DIR("features", aa_fs_entry_features),
	{ }
	};

	static struct aa_fs_entry aa_fs_entry =
	AA_FS_DIR("apparmor", aa_fs_entry_apparmor);

	/**
	* aafs_create_file - create a file entry in the apparmor securityfs
	* @fs_file: aa_fs_entry to build an entry for (NOT NULL)
	* @parent: the parent dentry in the securityfs
	*
	* Use aafs_remove_file to remove entries created with this fn.
	*/
	static int __init aafs_create_file(struct aa_fs_entry *fs_file,
	struct dentry *parent)
	{
	int error = 0;

	fs_file->dentry = securityfs_create_file(fs_file->name,
	S_IFREG \| fs_file->mode,
	parent, fs_file,
	fs_file->file_ops);
	if (IS_ERR(fs_file->dentry)) {
	error = PTR_ERR(fs_file->dentry);
	fs_file->dentry = NULL;
	}
	return error;
	}

	/**
	* aafs_create_dir - recursively create a directory entry in the securityfs
	* @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
	* @parent: the parent dentry in the securityfs
	*
	* Use aafs_remove_dir to remove entries created with this fn.
	*/
	static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
	struct dentry *parent)
	{
	int error;
	struct aa_fs_entry *fs_file;

	fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
	if (IS_ERR(fs_dir->dentry)) {
	error = PTR_ERR(fs_dir->dentry);
	fs_dir->dentry = NULL;
	goto failed;
	}

	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
	if (fs_file->v_type == AA_FS_TYPE_DIR)
	error = aafs_create_dir(fs_file, fs_dir->dentry);
	else
	error = aafs_create_file(fs_file, fs_dir->dentry);
	if (error)
	goto failed;
	}

	return 0;

	failed:
	return error;
	}

	/**
	* aafs_remove_file - drop a single file entry in the apparmor securityfs
	* @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
	*/
	static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
	{
	if (!fs_file->dentry)
	return;

	securityfs_remove(fs_file->dentry);
	fs_file->dentry = NULL;
	}

	/**
	* aafs_remove_dir - recursively drop a directory entry from the securityfs
	* @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
	*/
	static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
	{
	struct aa_fs_entry *fs_file;

	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
	if (fs_file->v_type == AA_FS_TYPE_DIR)
	aafs_remove_dir(fs_file);
	else
	aafs_remove_file(fs_file);
	}

	aafs_remove_file(fs_dir);
	}

	/**
	* aa_destroy_aafs - cleanup and free aafs
	*
	* releases dentries allocated by aa_create_aafs
	*/
	void __init aa_destroy_aafs(void)
	{
	aafs_remove_dir(&aa_fs_entry);
	}

	/**
	* aa_create_aafs - create the apparmor security filesystem
	*
	* dentries created here are released by aa_destroy_aafs
	*
	* Returns: error on failure
	*/
	static int __init aa_create_aafs(void)
	{
	int error;

	if (!apparmor_initialized)
	return 0;

	if (aa_fs_entry.dentry) {
	AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
	return -EEXIST;
	}

	/* Populate fs tree. */
	error = aafs_create_dir(&aa_fs_entry, NULL);
	if (error)
	goto error;

	/* TODO: add support for apparmorfs_null and apparmorfs_mnt */

	/* Report that AppArmor fs is enabled */
	aa_info_message("AppArmor Filesystem Enabled");
	return 0;

	error:
	aa_destroy_aafs();
	AA_ERROR("Error creating AppArmor securityfs\n");
	return error;
	}

	fs_initcall(aa_create_aafs);