[mirror_ubuntu-bionic-kernel.git] / security / integrity / ima / ima_policy.c

/*
 * Copyright (C) 2008 IBM Corporation
 * Author: Mimi Zohar <zohar@us.ibm.com>
 *
 * 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.
 *
 * ima_policy.c
 * 	- initialize default measure policy rules
 *
 */
#include <linux/module.h>
#include <linux/list.h>
#include <linux/security.h>
#include <linux/magic.h>
#include <linux/parser.h>

#include "ima.h"

/* flags definitions */
#define IMA_FUNC 	0x0001
#define IMA_MASK 	0x0002
#define IMA_FSMAGIC	0x0004
#define IMA_UID		0x0008

enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };

#define MAX_LSM_RULES 6
enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
	LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
};

struct ima_measure_rule_entry {
	struct list_head list;
	enum ima_action action;
	unsigned int flags;
	enum ima_hooks func;
	int mask;
	unsigned long fsmagic;
	uid_t uid;
	struct {
		void *rule;	/* LSM file metadata specific */
		int type;	/* audit type */
	} lsm[MAX_LSM_RULES];
};

/*
 * Without LSM specific knowledge, the default policy can only be
 * written in terms of .action, .func, .mask, .fsmagic, and .uid
 */

/*
 * The minimum rule set to allow for full TCB coverage.  Measures all files
 * opened or mmap for exec and everything read by root.  Dangerous because
 * normal users can easily run the machine out of memory simply building
 * and running executables.
 */
static struct ima_measure_rule_entry default_rules[] = {
	{.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
	{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
	{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
	{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
	{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
	{.action = DONT_MEASURE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
	{.action = MEASURE,.func = FILE_MMAP,.mask = MAY_EXEC,
	 .flags = IMA_FUNC | IMA_MASK},
	{.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
	 .flags = IMA_FUNC | IMA_MASK},
	{.action = MEASURE,.func = PATH_CHECK,.mask = MAY_READ,.uid = 0,
	 .flags = IMA_FUNC | IMA_MASK | IMA_UID},
};

static LIST_HEAD(measure_default_rules);
static LIST_HEAD(measure_policy_rules);
static struct list_head *ima_measure;

static DEFINE_MUTEX(ima_measure_mutex);

static bool ima_use_tcb __initdata;
static int __init default_policy_setup(char *str)
{
	ima_use_tcb = 1;
	return 1;
}
__setup("ima_tcb", default_policy_setup);

/**
 * ima_match_rules - determine whether an inode matches the measure rule.
 * @rule: a pointer to a rule
 * @inode: a pointer to an inode
 * @func: LIM hook identifier
 * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
 *
 * Returns true on rule match, false on failure.
 */
static bool ima_match_rules(struct ima_measure_rule_entry *rule,
			    struct inode *inode, enum ima_hooks func, int mask)
{
	struct task_struct *tsk = current;
	int i;

	if ((rule->flags & IMA_FUNC) && rule->func != func)
		return false;
	if ((rule->flags & IMA_MASK) && rule->mask != mask)
		return false;
	if ((rule->flags & IMA_FSMAGIC)
	    && rule->fsmagic != inode->i_sb->s_magic)
		return false;
	if ((rule->flags & IMA_UID) && rule->uid != tsk->cred->uid)
		return false;
	for (i = 0; i < MAX_LSM_RULES; i++) {
		int rc = 0;
		u32 osid, sid;

		if (!rule->lsm[i].rule)
			continue;

		switch (i) {
		case LSM_OBJ_USER:
		case LSM_OBJ_ROLE:
		case LSM_OBJ_TYPE:
			security_inode_getsecid(inode, &osid);
			rc = security_filter_rule_match(osid,
							rule->lsm[i].type,
							Audit_equal,
							rule->lsm[i].rule,
							NULL);
			break;
		case LSM_SUBJ_USER:
		case LSM_SUBJ_ROLE:
		case LSM_SUBJ_TYPE:
			security_task_getsecid(tsk, &sid);
			rc = security_filter_rule_match(sid,
							rule->lsm[i].type,
							Audit_equal,
							rule->lsm[i].rule,
							NULL);
		default:
			break;
		}
		if (!rc)
			return false;
	}
	return true;
}

/**
 * ima_match_policy - decision based on LSM and other conditions
 * @inode: pointer to an inode for which the policy decision is being made
 * @func: IMA hook identifier
 * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
 *
 * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
 * conditions.
 *
 * (There is no need for locking when walking the policy list,
 * as elements in the list are never deleted, nor does the list
 * change.)
 */
int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
{
	struct ima_measure_rule_entry *entry;

	list_for_each_entry(entry, ima_measure, list) {
		bool rc;

		rc = ima_match_rules(entry, inode, func, mask);
		if (rc)
			return entry->action;
	}
	return 0;
}

/**
 * ima_init_policy - initialize the default measure rules.
 *
 * ima_measure points to either the measure_default_rules or the
 * the new measure_policy_rules.
 */
void ima_init_policy(void)
{
	int i, entries;

	/* if !ima_use_tcb set entries = 0 so we load NO default rules */
	if (ima_use_tcb)
		entries = ARRAY_SIZE(default_rules);
	else
		entries = 0;

	for (i = 0; i < entries; i++)
		list_add_tail(&default_rules[i].list, &measure_default_rules);
	ima_measure = &measure_default_rules;
}

/**
 * ima_update_policy - update default_rules with new measure rules
 *
 * Called on file .release to update the default rules with a complete new
 * policy.  Once updated, the policy is locked, no additional rules can be
 * added to the policy.
 */
void ima_update_policy(void)
{
	const char *op = "policy_update";
	const char *cause = "already exists";
	int result = 1;
	int audit_info = 0;

	if (ima_measure == &measure_default_rules) {
		ima_measure = &measure_policy_rules;
		cause = "complete";
		result = 0;
	}
	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
			    NULL, op, cause, result, audit_info);
}

enum {
	Opt_err = -1,
	Opt_measure = 1, Opt_dont_measure,
	Opt_obj_user, Opt_obj_role, Opt_obj_type,
	Opt_subj_user, Opt_subj_role, Opt_subj_type,
	Opt_func, Opt_mask, Opt_fsmagic, Opt_uid
};

static match_table_t policy_tokens = {
	{Opt_measure, "measure"},
	{Opt_dont_measure, "dont_measure"},
	{Opt_obj_user, "obj_user=%s"},
	{Opt_obj_role, "obj_role=%s"},
	{Opt_obj_type, "obj_type=%s"},
	{Opt_subj_user, "subj_user=%s"},
	{Opt_subj_role, "subj_role=%s"},
	{Opt_subj_type, "subj_type=%s"},
	{Opt_func, "func=%s"},
	{Opt_mask, "mask=%s"},
	{Opt_fsmagic, "fsmagic=%s"},
	{Opt_uid, "uid=%s"},
	{Opt_err, NULL}
};

static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
			     char *args, int lsm_rule, int audit_type)
{
	int result;

	entry->lsm[lsm_rule].type = audit_type;
	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
					   Audit_equal, args,
					   &entry->lsm[lsm_rule].rule);
	return result;
}

static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
{
	struct audit_buffer *ab;
	char *p;
	int result = 0;

	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);

	entry->action = -1;
	while ((p = strsep(&rule, " \n")) != NULL) {
		substring_t args[MAX_OPT_ARGS];
		int token;
		unsigned long lnum;

		if (result < 0)
			break;
		if (!*p)
			continue;
		token = match_token(p, policy_tokens, args);
		switch (token) {
		case Opt_measure:
			audit_log_format(ab, "%s ", "measure");
			entry->action = MEASURE;
			break;
		case Opt_dont_measure:
			audit_log_format(ab, "%s ", "dont_measure");
			entry->action = DONT_MEASURE;
			break;
		case Opt_func:
			audit_log_format(ab, "func=%s ", args[0].from);
			if (strcmp(args[0].from, "PATH_CHECK") == 0)
				entry->func = PATH_CHECK;
			else if (strcmp(args[0].from, "FILE_MMAP") == 0)
				entry->func = FILE_MMAP;
			else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
				entry->func = BPRM_CHECK;
			else
				result = -EINVAL;
			if (!result)
				entry->flags |= IMA_FUNC;
			break;
		case Opt_mask:
			audit_log_format(ab, "mask=%s ", args[0].from);
			if ((strcmp(args[0].from, "MAY_EXEC")) == 0)
				entry->mask = MAY_EXEC;
			else if (strcmp(args[0].from, "MAY_WRITE") == 0)
				entry->mask = MAY_WRITE;
			else if (strcmp(args[0].from, "MAY_READ") == 0)
				entry->mask = MAY_READ;
			else if (strcmp(args[0].from, "MAY_APPEND") == 0)
				entry->mask = MAY_APPEND;
			else
				result = -EINVAL;
			if (!result)
				entry->flags |= IMA_MASK;
			break;
		case Opt_fsmagic:
			audit_log_format(ab, "fsmagic=%s ", args[0].from);
			result = strict_strtoul(args[0].from, 16,
						&entry->fsmagic);
			if (!result)
				entry->flags |= IMA_FSMAGIC;
			break;
		case Opt_uid:
			audit_log_format(ab, "uid=%s ", args[0].from);
			result = strict_strtoul(args[0].from, 10, &lnum);
			if (!result) {
				entry->uid = (uid_t) lnum;
				if (entry->uid != lnum)
					result = -EINVAL;
				else
					entry->flags |= IMA_UID;
			}
			break;
		case Opt_obj_user:
			audit_log_format(ab, "obj_user=%s ", args[0].from);
			result = ima_lsm_rule_init(entry, args[0].from,
						   LSM_OBJ_USER,
						   AUDIT_OBJ_USER);
			break;
		case Opt_obj_role:
			audit_log_format(ab, "obj_role=%s ", args[0].from);
			result = ima_lsm_rule_init(entry, args[0].from,
						   LSM_OBJ_ROLE,
						   AUDIT_OBJ_ROLE);
			break;
		case Opt_obj_type:
			audit_log_format(ab, "obj_type=%s ", args[0].from);
			result = ima_lsm_rule_init(entry, args[0].from,
						   LSM_OBJ_TYPE,
						   AUDIT_OBJ_TYPE);
			break;
		case Opt_subj_user:
			audit_log_format(ab, "subj_user=%s ", args[0].from);
			result = ima_lsm_rule_init(entry, args[0].from,
						   LSM_SUBJ_USER,
						   AUDIT_SUBJ_USER);
			break;
		case Opt_subj_role:
			audit_log_format(ab, "subj_role=%s ", args[0].from);
			result = ima_lsm_rule_init(entry, args[0].from,
						   LSM_SUBJ_ROLE,
						   AUDIT_SUBJ_ROLE);
			break;
		case Opt_subj_type:
			audit_log_format(ab, "subj_type=%s ", args[0].from);
			result = ima_lsm_rule_init(entry, args[0].from,
						   LSM_SUBJ_TYPE,
						   AUDIT_SUBJ_TYPE);
			break;
		case Opt_err:
			audit_log_format(ab, "UNKNOWN=%s ", p);
			break;
		}
	}
	if (entry->action == UNKNOWN)
		result = -EINVAL;

	audit_log_format(ab, "res=%d", !result ? 0 : 1);
	audit_log_end(ab);
	return result;
}

/**
 * ima_parse_add_rule - add a rule to measure_policy_rules
 * @rule - ima measurement policy rule
 *
 * Uses a mutex to protect the policy list from multiple concurrent writers.
 * Returns 0 on success, an error code on failure.
 */
int ima_parse_add_rule(char *rule)
{
	const char *op = "update_policy";
	struct ima_measure_rule_entry *entry;
	int result = 0;
	int audit_info = 0;

	/* Prevent installed policy from changing */
	if (ima_measure != &measure_default_rules) {
		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
				    NULL, op, "already exists",
				    -EACCES, audit_info);
		return -EACCES;
	}

	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
	if (!entry) {
		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
				    NULL, op, "-ENOMEM", -ENOMEM, audit_info);
		return -ENOMEM;
	}

	INIT_LIST_HEAD(&entry->list);

	result = ima_parse_rule(rule, entry);
	if (!result) {
		mutex_lock(&ima_measure_mutex);
		list_add_tail(&entry->list, &measure_policy_rules);
		mutex_unlock(&ima_measure_mutex);
	} else {
		kfree(entry);
		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
				    NULL, op, "invalid policy", result,
				    audit_info);
	}
	return result;
}

/* ima_delete_rules called to cleanup invalid policy */
void ima_delete_rules(void)
{
	struct ima_measure_rule_entry *entry, *tmp;

	mutex_lock(&ima_measure_mutex);
	list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) {
		list_del(&entry->list);
		kfree(entry);
	}
	mutex_unlock(&ima_measure_mutex);
}
Commit	Line	Data
3323eec9 MZ	1	/*
	2	* Copyright (C) 2008 IBM Corporation
	3	* Author: Mimi Zohar <zohar@us.ibm.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation, version 2 of the License.
	8	*
	9	* ima_policy.c
	10	* - initialize default measure policy rules
	11	*
	12	*/
	13	#include <linux/module.h>
	14	#include <linux/list.h>
3323eec9 MZ	15	#include <linux/security.h>
3323eec9 MZ	16	#include <linux/magic.h>
4af4662f	17	#include <linux/parser.h>
3323eec9 MZ	18
	19	#include "ima.h"
	20
	21	/* flags definitions */
	22	#define IMA_FUNC 0x0001
	23	#define IMA_MASK 0x0002
	24	#define IMA_FSMAGIC 0x0004
	25	#define IMA_UID 0x0008
	26
4af4662f MZ	27	enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };
	28
	29	#define MAX_LSM_RULES 6
	30	enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
	31	LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
	32	};
3323eec9 MZ	33
	34	struct ima_measure_rule_entry {
	35	struct list_head list;
	36	enum ima_action action;
	37	unsigned int flags;
	38	enum ima_hooks func;
	39	int mask;
	40	unsigned long fsmagic;
	41	uid_t uid;
4af4662f MZ	42	struct {
	43	void rule; / LSM file metadata specific */
	44	int type; /* audit type */
	45	} lsm[MAX_LSM_RULES];
3323eec9 MZ	46	};
3323eec9 MZ	47
5789ba3b EP	48	/*
5789ba3b EP	49	* Without LSM specific knowledge, the default policy can only be
4af4662f MZ	50	* written in terms of .action, .func, .mask, .fsmagic, and .uid
4af4662f MZ	51	*/
5789ba3b EP	52
	53	/*
	54	* The minimum rule set to allow for full TCB coverage. Measures all files
	55	* opened or mmap for exec and everything read by root. Dangerous because
	56	* normal users can easily run the machine out of memory simply building
	57	* and running executables.
	58	*/
3323eec9	59	static struct ima_measure_rule_entry default_rules[] = {
75834fc3	60	{.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
3323eec9 MZ	61	{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
	62	{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
	63	{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
75834fc3 EP	64	{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
75834fc3 EP	65	{.action = DONT_MEASURE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
3323eec9 MZ	66	{.action = MEASURE,.func = FILE_MMAP,.mask = MAY_EXEC,
	67	.flags = IMA_FUNC \| IMA_MASK},
	68	{.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
	69	.flags = IMA_FUNC \| IMA_MASK},
5789ba3b EP	70	{.action = MEASURE,.func = PATH_CHECK,.mask = MAY_READ,.uid = 0,
5789ba3b EP	71	.flags = IMA_FUNC \| IMA_MASK \| IMA_UID},
3323eec9 MZ	72	};
	73
	74	static LIST_HEAD(measure_default_rules);
4af4662f	75	static LIST_HEAD(measure_policy_rules);
3323eec9 MZ	76	static struct list_head *ima_measure;
3323eec9 MZ	77
4af4662f MZ	78	static DEFINE_MUTEX(ima_measure_mutex);
4af4662f MZ	79
5789ba3b EP	80	static bool ima_use_tcb __initdata;
	81	static int __init default_policy_setup(char *str)
	82	{
	83	ima_use_tcb = 1;
	84	return 1;
	85	}
	86	__setup("ima_tcb", default_policy_setup);
	87
3323eec9 MZ	88	/**
	89	* ima_match_rules - determine whether an inode matches the measure rule.
	90	* @rule: a pointer to a rule
	91	* @inode: a pointer to an inode
	92	* @func: LIM hook identifier
	93	* @mask: requested action (MAY_READ \| MAY_WRITE \| MAY_APPEND \| MAY_EXEC)
	94	*
	95	* Returns true on rule match, false on failure.
	96	*/
	97	static bool ima_match_rules(struct ima_measure_rule_entry *rule,
	98	struct inode *inode, enum ima_hooks func, int mask)
	99	{
	100	struct task_struct *tsk = current;
4af4662f	101	int i;
3323eec9 MZ	102
	103	if ((rule->flags & IMA_FUNC) && rule->func != func)
	104	return false;
	105	if ((rule->flags & IMA_MASK) && rule->mask != mask)
	106	return false;
	107	if ((rule->flags & IMA_FSMAGIC)
	108	&& rule->fsmagic != inode->i_sb->s_magic)
	109	return false;
	110	if ((rule->flags & IMA_UID) && rule->uid != tsk->cred->uid)
	111	return false;
4af4662f	112	for (i = 0; i < MAX_LSM_RULES; i++) {
53fc0e22	113	int rc = 0;
4af4662f MZ	114	u32 osid, sid;
	115
	116	if (!rule->lsm[i].rule)
	117	continue;
	118
	119	switch (i) {
	120	case LSM_OBJ_USER:
	121	case LSM_OBJ_ROLE:
	122	case LSM_OBJ_TYPE:
	123	security_inode_getsecid(inode, &osid);
	124	rc = security_filter_rule_match(osid,
	125	rule->lsm[i].type,
53fc0e22	126	Audit_equal,
4af4662f MZ	127	rule->lsm[i].rule,
	128	NULL);
	129	break;
	130	case LSM_SUBJ_USER:
	131	case LSM_SUBJ_ROLE:
	132	case LSM_SUBJ_TYPE:
	133	security_task_getsecid(tsk, &sid);
	134	rc = security_filter_rule_match(sid,
	135	rule->lsm[i].type,
53fc0e22	136	Audit_equal,
4af4662f MZ	137	rule->lsm[i].rule,
	138	NULL);
	139	default:
	140	break;
	141	}
	142	if (!rc)
	143	return false;
	144	}
3323eec9 MZ	145	return true;
	146	}
	147
	148	/**
	149	* ima_match_policy - decision based on LSM and other conditions
	150	* @inode: pointer to an inode for which the policy decision is being made
	151	* @func: IMA hook identifier
	152	* @mask: requested action (MAY_READ \| MAY_WRITE \| MAY_APPEND \| MAY_EXEC)
	153	*
	154	* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
	155	* conditions.
	156	*
	157	* (There is no need for locking when walking the policy list,
	158	* as elements in the list are never deleted, nor does the list
	159	* change.)
	160	*/
	161	int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
	162	{
	163	struct ima_measure_rule_entry *entry;
	164
	165	list_for_each_entry(entry, ima_measure, list) {
	166	bool rc;
	167
	168	rc = ima_match_rules(entry, inode, func, mask);
	169	if (rc)
	170	return entry->action;
	171	}
	172	return 0;
	173	}
	174
	175	/**
	176	* ima_init_policy - initialize the default measure rules.
	177	*
3323eec9	178	* ima_measure points to either the measure_default_rules or the
4af4662f	179	* the new measure_policy_rules.
3323eec9 MZ	180	*/
	181	void ima_init_policy(void)
	182	{
5789ba3b EP	183	int i, entries;
	184
	185	/* if !ima_use_tcb set entries = 0 so we load NO default rules */
	186	if (ima_use_tcb)
	187	entries = ARRAY_SIZE(default_rules);
	188	else
	189	entries = 0;
3323eec9	190
5789ba3b	191	for (i = 0; i < entries; i++)
3323eec9 MZ	192	list_add_tail(&default_rules[i].list, &measure_default_rules);
	193	ima_measure = &measure_default_rules;
	194	}
4af4662f MZ	195
	196	/**
	197	* ima_update_policy - update default_rules with new measure rules
	198	*
	199	* Called on file .release to update the default rules with a complete new
	200	* policy. Once updated, the policy is locked, no additional rules can be
	201	* added to the policy.
	202	*/
	203	void ima_update_policy(void)
	204	{
	205	const char *op = "policy_update";
	206	const char *cause = "already exists";
	207	int result = 1;
	208	int audit_info = 0;
	209
	210	if (ima_measure == &measure_default_rules) {
	211	ima_measure = &measure_policy_rules;
	212	cause = "complete";
	213	result = 0;
	214	}
	215	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	216	NULL, op, cause, result, audit_info);
	217	}
	218
	219	enum {
	220	Opt_err = -1,
	221	Opt_measure = 1, Opt_dont_measure,
	222	Opt_obj_user, Opt_obj_role, Opt_obj_type,
	223	Opt_subj_user, Opt_subj_role, Opt_subj_type,
	224	Opt_func, Opt_mask, Opt_fsmagic, Opt_uid
	225	};
	226
	227	static match_table_t policy_tokens = {
	228	{Opt_measure, "measure"},
	229	{Opt_dont_measure, "dont_measure"},
	230	{Opt_obj_user, "obj_user=%s"},
	231	{Opt_obj_role, "obj_role=%s"},
	232	{Opt_obj_type, "obj_type=%s"},
	233	{Opt_subj_user, "subj_user=%s"},
	234	{Opt_subj_role, "subj_role=%s"},
	235	{Opt_subj_type, "subj_type=%s"},
	236	{Opt_func, "func=%s"},
	237	{Opt_mask, "mask=%s"},
	238	{Opt_fsmagic, "fsmagic=%s"},
	239	{Opt_uid, "uid=%s"},
	240	{Opt_err, NULL}
	241	};
	242
	243	static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
	244	char *args, int lsm_rule, int audit_type)
	245	{
	246	int result;
	247
	248	entry->lsm[lsm_rule].type = audit_type;
	249	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
53fc0e22	250	Audit_equal, args,
4af4662f MZ	251	&entry->lsm[lsm_rule].rule);
	252	return result;
	253	}
	254
	255	static int ima_parse_rule(char rule, struct ima_measure_rule_entry entry)
	256	{
	257	struct audit_buffer *ab;
	258	char *p;
	259	int result = 0;
	260
523979ad	261	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
4af4662f MZ	262
	263	entry->action = -1;
	264	while ((p = strsep(&rule, " \n")) != NULL) {
	265	substring_t args[MAX_OPT_ARGS];
	266	int token;
	267	unsigned long lnum;
	268
	269	if (result < 0)
	270	break;
	271	if (!*p)
	272	continue;
	273	token = match_token(p, policy_tokens, args);
	274	switch (token) {
	275	case Opt_measure:
	276	audit_log_format(ab, "%s ", "measure");
	277	entry->action = MEASURE;
	278	break;
	279	case Opt_dont_measure:
	280	audit_log_format(ab, "%s ", "dont_measure");
	281	entry->action = DONT_MEASURE;
	282	break;
	283	case Opt_func:
	284	audit_log_format(ab, "func=%s ", args[0].from);
	285	if (strcmp(args[0].from, "PATH_CHECK") == 0)
	286	entry->func = PATH_CHECK;
	287	else if (strcmp(args[0].from, "FILE_MMAP") == 0)
	288	entry->func = FILE_MMAP;
	289	else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
	290	entry->func = BPRM_CHECK;
	291	else
	292	result = -EINVAL;
	293	if (!result)
	294	entry->flags \|= IMA_FUNC;
	295	break;
	296	case Opt_mask:
	297	audit_log_format(ab, "mask=%s ", args[0].from);
	298	if ((strcmp(args[0].from, "MAY_EXEC")) == 0)
	299	entry->mask = MAY_EXEC;
	300	else if (strcmp(args[0].from, "MAY_WRITE") == 0)
	301	entry->mask = MAY_WRITE;
	302	else if (strcmp(args[0].from, "MAY_READ") == 0)
	303	entry->mask = MAY_READ;
	304	else if (strcmp(args[0].from, "MAY_APPEND") == 0)
	305	entry->mask = MAY_APPEND;
	306	else
	307	result = -EINVAL;
	308	if (!result)
	309	entry->flags \|= IMA_MASK;
	310	break;
	311	case Opt_fsmagic:
	312	audit_log_format(ab, "fsmagic=%s ", args[0].from);
	313	result = strict_strtoul(args[0].from, 16,
	314	&entry->fsmagic);
	315	if (!result)
	316	entry->flags \|= IMA_FSMAGIC;
	317	break;
	318	case Opt_uid:
	319	audit_log_format(ab, "uid=%s ", args[0].from);
	320	result = strict_strtoul(args[0].from, 10, &lnum);
	321	if (!result) {
	322	entry->uid = (uid_t) lnum;
	323	if (entry->uid != lnum)
	324	result = -EINVAL;
	325	else
326	entry->flags \|= IMA_UID;
327	}
328	break;
329	case Opt_obj_user:
330	audit_log_format(ab, "obj_user=%s ", args[0].from);
331	result = ima_lsm_rule_init(entry, args[0].from,
332	LSM_OBJ_USER,
333	AUDIT_OBJ_USER);
334	break;
335	case Opt_obj_role:
336	audit_log_format(ab, "obj_role=%s ", args[0].from);
337	result = ima_lsm_rule_init(entry, args[0].from,
338	LSM_OBJ_ROLE,
339	AUDIT_OBJ_ROLE);
340	break;
341	case Opt_obj_type:
342	audit_log_format(ab, "obj_type=%s ", args[0].from);
343	result = ima_lsm_rule_init(entry, args[0].from,
344	LSM_OBJ_TYPE,
345	AUDIT_OBJ_TYPE);
346	break;
347	case Opt_subj_user:
348	audit_log_format(ab, "subj_user=%s ", args[0].from);
349	result = ima_lsm_rule_init(entry, args[0].from,
350	LSM_SUBJ_USER,
351	AUDIT_SUBJ_USER);
352	break;
353	case Opt_subj_role:
354	audit_log_format(ab, "subj_role=%s ", args[0].from);
355	result = ima_lsm_rule_init(entry, args[0].from,
356	LSM_SUBJ_ROLE,
357	AUDIT_SUBJ_ROLE);
358	break;
359	case Opt_subj_type:
360	audit_log_format(ab, "subj_type=%s ", args[0].from);
361	result = ima_lsm_rule_init(entry, args[0].from,
362	LSM_SUBJ_TYPE,
363	AUDIT_SUBJ_TYPE);
364	break;
365	case Opt_err:
523979ad	366	audit_log_format(ab, "UNKNOWN=%s ", p);
4af4662f MZ	367	break;
	368	}
	369	}
	370	if (entry->action == UNKNOWN)
	371	result = -EINVAL;
	372
523979ad	373	audit_log_format(ab, "res=%d", !result ? 0 : 1);
4af4662f MZ	374	audit_log_end(ab);
	375	return result;
	376	}
	377
	378	/**
	379	* ima_parse_add_rule - add a rule to measure_policy_rules
	380	* @rule - ima measurement policy rule
	381	*
	382	* Uses a mutex to protect the policy list from multiple concurrent writers.
	383	* Returns 0 on success, an error code on failure.
	384	*/
	385	int ima_parse_add_rule(char *rule)
	386	{
523979ad	387	const char *op = "update_policy";
4af4662f MZ	388	struct ima_measure_rule_entry *entry;
	389	int result = 0;
	390	int audit_info = 0;
	391
	392	/* Prevent installed policy from changing */
	393	if (ima_measure != &measure_default_rules) {
	394	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	395	NULL, op, "already exists",
	396	-EACCES, audit_info);
	397	return -EACCES;
	398	}
	399
	400	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
	401	if (!entry) {
	402	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	403	NULL, op, "-ENOMEM", -ENOMEM, audit_info);
	404	return -ENOMEM;
	405	}
	406
	407	INIT_LIST_HEAD(&entry->list);
	408
	409	result = ima_parse_rule(rule, entry);
	410	if (!result) {
	411	mutex_lock(&ima_measure_mutex);
	412	list_add_tail(&entry->list, &measure_policy_rules);
	413	mutex_unlock(&ima_measure_mutex);
523979ad	414	} else {
4af4662f	415	kfree(entry);
523979ad MZ	416	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	417	NULL, op, "invalid policy", result,
	418	audit_info);
	419	}
4af4662f MZ	420	return result;
	421	}
	422
	423	/* ima_delete_rules called to cleanup invalid policy */
64c61d80	424	void ima_delete_rules(void)
4af4662f MZ	425	{
	426	struct ima_measure_rule_entry entry, tmp;
	427
	428	mutex_lock(&ima_measure_mutex);
	429	list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) {
	430	list_del(&entry->list);
	431	kfree(entry);
	432	}
	433	mutex_unlock(&ima_measure_mutex);
	434	}