[GitHub/mt8127/android_kernel_alcatel_ttab.git] / security / apparmor / apparmorfs.c

/*
 * 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);
Commit	Line	Data
63e2b423 JJ	1	/*
	2	* AppArmor security module
	3	*
	4	* This file contains AppArmor /sys/kernel/security/apparmor interface functions
	5	*
	6	* Copyright (C) 1998-2008 Novell/SUSE
	7	* Copyright 2009-2010 Canonical Ltd.
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License as
	11	* published by the Free Software Foundation, version 2 of the
	12	* License.
	13	*/
	14
	15	#include <linux/security.h>
	16	#include <linux/vmalloc.h>
	17	#include <linux/module.h>
	18	#include <linux/seq_file.h>
	19	#include <linux/uaccess.h>
	20	#include <linux/namei.h>
e74abcf3	21	#include <linux/capability.h>
63e2b423 JJ	22
	23	#include "include/apparmor.h"
	24	#include "include/apparmorfs.h"
	25	#include "include/audit.h"
	26	#include "include/context.h"
	27	#include "include/policy.h"
d384b0a1	28	#include "include/resource.h"
63e2b423 JJ	29
	30	/**
	31	* aa_simple_write_to_buffer - common routine for getting policy from user
	32	* @op: operation doing the user buffer copy
	33	* @userbuf: user buffer to copy data from (NOT NULL)
3ed02ada	34	* @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
63e2b423 JJ	35	* @copy_size: size of data to copy from user buffer
	36	* @pos: position write is at in the file (NOT NULL)
	37	*
	38	* Returns: kernel buffer containing copy of user buffer data or an
	39	* ERR_PTR on failure.
	40	*/
	41	static char aa_simple_write_to_buffer(int op, const char __user userbuf,
	42	size_t alloc_size, size_t copy_size,
	43	loff_t *pos)
	44	{
	45	char *data;
	46
3ed02ada JJ	47	BUG_ON(copy_size > alloc_size);
3ed02ada JJ	48
63e2b423 JJ	49	if (*pos != 0)
	50	/* only writes from pos 0, that is complete writes */
	51	return ERR_PTR(-ESPIPE);
	52
	53	/*
	54	* Don't allow profile load/replace/remove from profiles that don't
	55	* have CAP_MAC_ADMIN
	56	*/
	57	if (!aa_may_manage_policy(op))
	58	return ERR_PTR(-EACCES);
	59
	60	/* freed by caller to simple_write_to_buffer */
	61	data = kvmalloc(alloc_size);
	62	if (data == NULL)
	63	return ERR_PTR(-ENOMEM);
	64
	65	if (copy_from_user(data, userbuf, copy_size)) {
	66	kvfree(data);
	67	return ERR_PTR(-EFAULT);
	68	}
	69
	70	return data;
	71	}
	72
	73
	74	/* .load file hook fn to load policy */
	75	static ssize_t profile_load(struct file f, const char __user buf, size_t size,
	76	loff_t *pos)
	77	{
	78	char *data;
	79	ssize_t error;
	80
	81	data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos);
	82
	83	error = PTR_ERR(data);
	84	if (!IS_ERR(data)) {
	85	error = aa_replace_profiles(data, size, PROF_ADD);
	86	kvfree(data);
	87	}
	88
	89	return error;
	90	}
	91
	92	static const struct file_operations aa_fs_profile_load = {
6038f373 AB	93	.write = profile_load,
6038f373 AB	94	.llseek = default_llseek,
63e2b423 JJ	95	};
	96
	97	/* .replace file hook fn to load and/or replace policy */
	98	static ssize_t profile_replace(struct file f, const char __user buf,
	99	size_t size, loff_t *pos)
	100	{
	101	char *data;
	102	ssize_t error;
	103
	104	data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos);
	105	error = PTR_ERR(data);
	106	if (!IS_ERR(data)) {
	107	error = aa_replace_profiles(data, size, PROF_REPLACE);
	108	kvfree(data);
	109	}
	110
	111	return error;
	112	}
	113
	114	static const struct file_operations aa_fs_profile_replace = {
6038f373 AB	115	.write = profile_replace,
6038f373 AB	116	.llseek = default_llseek,
63e2b423 JJ	117	};
	118
	119	/* .remove file hook fn to remove loaded policy */
	120	static ssize_t profile_remove(struct file f, const char __user buf,
	121	size_t size, loff_t *pos)
	122	{
	123	char *data;
	124	ssize_t error;
	125
	126	/*
	127	* aa_remove_profile needs a null terminated string so 1 extra
	128	* byte is allocated and the copied data is null terminated.
	129	*/
	130	data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos);
	131
	132	error = PTR_ERR(data);
	133	if (!IS_ERR(data)) {
	134	data[size] = 0;
	135	error = aa_remove_profiles(data, size);
	136	kvfree(data);
	137	}
	138
	139	return error;
	140	}
	141
	142	static const struct file_operations aa_fs_profile_remove = {
6038f373 AB	143	.write = profile_remove,
6038f373 AB	144	.llseek = default_llseek,
63e2b423 JJ	145	};
63e2b423 JJ	146
e74abcf3 KC	147	static int aa_fs_seq_show(struct seq_file seq, void v)
	148	{
	149	struct aa_fs_entry *fs_file = seq->private;
	150
	151	if (!fs_file)
	152	return 0;
	153
	154	switch (fs_file->v_type) {
	155	case AA_FS_TYPE_BOOLEAN:
	156	seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
	157	break;
a9bf8e9f KC	158	case AA_FS_TYPE_STRING:
	159	seq_printf(seq, "%s\n", fs_file->v.string);
	160	break;
e74abcf3 KC	161	case AA_FS_TYPE_U64:
	162	seq_printf(seq, "%#08lx\n", fs_file->v.u64);
	163	break;
	164	default:
	165	/* Ignore unpritable entry types. */
	166	break;
	167	}
	168
	169	return 0;
	170	}
	171
	172	static int aa_fs_seq_open(struct inode inode, struct file file)
	173	{
	174	return single_open(file, aa_fs_seq_show, inode->i_private);
	175	}
	176
	177	const struct file_operations aa_fs_seq_file_ops = {
	178	.owner = THIS_MODULE,
	179	.open = aa_fs_seq_open,
	180	.read = seq_read,
	181	.llseek = seq_lseek,
	182	.release = single_release,
	183	};
	184
63e2b423 JJ	185	/ Base file system setup /
63e2b423 JJ	186
a9bf8e9f KC	187	static struct aa_fs_entry aa_fs_entry_file[] = {
	188	AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \
	189	"link lock"),
	190	{ }
	191	};
	192
e74abcf3 KC	193	static struct aa_fs_entry aa_fs_entry_domain[] = {
	194	AA_FS_FILE_BOOLEAN("change_hat", 1),
	195	AA_FS_FILE_BOOLEAN("change_hatv", 1),
	196	AA_FS_FILE_BOOLEAN("change_onexec", 1),
	197	AA_FS_FILE_BOOLEAN("change_profile", 1),
	198	{ }
	199	};
	200
	201	static struct aa_fs_entry aa_fs_entry_features[] = {
	202	AA_FS_DIR("domain", aa_fs_entry_domain),
a9bf8e9f	203	AA_FS_DIR("file", aa_fs_entry_file),
e74abcf3	204	AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK),
d384b0a1	205	AA_FS_DIR("rlimit", aa_fs_entry_rlimit),
e74abcf3 KC	206	{ }
	207	};
	208
9acd494b KC	209	static struct aa_fs_entry aa_fs_entry_apparmor[] = {
	210	AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),
	211	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
	212	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
e74abcf3	213	AA_FS_DIR("features", aa_fs_entry_features),
9acd494b KC	214	{ }
9acd494b KC	215	};
63e2b423	216
9acd494b KC	217	static struct aa_fs_entry aa_fs_entry =
9acd494b KC	218	AA_FS_DIR("apparmor", aa_fs_entry_apparmor);
63e2b423	219
9acd494b KC	220	/**
	221	* aafs_create_file - create a file entry in the apparmor securityfs
	222	* @fs_file: aa_fs_entry to build an entry for (NOT NULL)
	223	* @parent: the parent dentry in the securityfs
	224	*
	225	* Use aafs_remove_file to remove entries created with this fn.
	226	*/
	227	static int __init aafs_create_file(struct aa_fs_entry *fs_file,
	228	struct dentry *parent)
	229	{
	230	int error = 0;
	231
	232	fs_file->dentry = securityfs_create_file(fs_file->name,
	233	S_IFREG \| fs_file->mode,
	234	parent, fs_file,
	235	fs_file->file_ops);
	236	if (IS_ERR(fs_file->dentry)) {
	237	error = PTR_ERR(fs_file->dentry);
	238	fs_file->dentry = NULL;
63e2b423	239	}
9acd494b	240	return error;
63e2b423 JJ	241	}
	242
	243	/**
9acd494b KC	244	* aafs_create_dir - recursively create a directory entry in the securityfs
	245	* @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
	246	* @parent: the parent dentry in the securityfs
63e2b423	247	*
9acd494b	248	* Use aafs_remove_dir to remove entries created with this fn.
63e2b423	249	*/
9acd494b KC	250	static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
9acd494b KC	251	struct dentry *parent)
63e2b423	252	{
9acd494b KC	253	int error;
9acd494b KC	254	struct aa_fs_entry *fs_file;
63e2b423	255
9acd494b KC	256	fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
	257	if (IS_ERR(fs_dir->dentry)) {
	258	error = PTR_ERR(fs_dir->dentry);
	259	fs_dir->dentry = NULL;
	260	goto failed;
	261	}
63e2b423	262
9acd494b KC	263	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
	264	if (fs_file->v_type == AA_FS_TYPE_DIR)
	265	error = aafs_create_dir(fs_file, fs_dir->dentry);
	266	else
	267	error = aafs_create_file(fs_file, fs_dir->dentry);
	268	if (error)
	269	goto failed;
	270	}
	271
	272	return 0;
	273
	274	failed:
	275	return error;
	276	}
	277
	278	/**
	279	* aafs_remove_file - drop a single file entry in the apparmor securityfs
	280	* @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
	281	*/
	282	static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
	283	{
	284	if (!fs_file->dentry)
	285	return;
	286
	287	securityfs_remove(fs_file->dentry);
	288	fs_file->dentry = NULL;
	289	}
	290
	291	/**
	292	* aafs_remove_dir - recursively drop a directory entry from the securityfs
	293	* @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
	294	*/
	295	static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
	296	{
	297	struct aa_fs_entry *fs_file;
	298
	299	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
	300	if (fs_file->v_type == AA_FS_TYPE_DIR)
	301	aafs_remove_dir(fs_file);
	302	else
	303	aafs_remove_file(fs_file);
	304	}
	305
	306	aafs_remove_file(fs_dir);
63e2b423 JJ	307	}
	308
	309	/**
	310	* aa_destroy_aafs - cleanup and free aafs
	311	*
	312	* releases dentries allocated by aa_create_aafs
	313	*/
	314	void __init aa_destroy_aafs(void)
	315	{
9acd494b	316	aafs_remove_dir(&aa_fs_entry);
63e2b423 JJ	317	}
	318
	319	/**
	320	* aa_create_aafs - create the apparmor security filesystem
	321	*
	322	* dentries created here are released by aa_destroy_aafs
	323	*
	324	* Returns: error on failure
	325	*/
3417d8d5	326	static int __init aa_create_aafs(void)
63e2b423 JJ	327	{
	328	int error;
	329
	330	if (!apparmor_initialized)
	331	return 0;
	332
9acd494b	333	if (aa_fs_entry.dentry) {
63e2b423 JJ	334	AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
	335	return -EEXIST;
	336	}
	337
9acd494b KC	338	/* Populate fs tree. */
9acd494b KC	339	error = aafs_create_dir(&aa_fs_entry, NULL);
63e2b423 JJ	340	if (error)
	341	goto error;
	342
	343	/* TODO: add support for apparmorfs_null and apparmorfs_mnt */
	344
	345	/* Report that AppArmor fs is enabled */
	346	aa_info_message("AppArmor Filesystem Enabled");
	347	return 0;
	348
	349	error:
	350	aa_destroy_aafs();
	351	AA_ERROR("Error creating AppArmor securityfs\n");
	352	return error;
	353	}
	354
	355	fs_initcall(aa_create_aafs);