[deliverable/linux.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
 */
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 = 0xF97CFF8C,.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);

/**
 * 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;
		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;

	for (i = 0; i < ARRAY_SIZE(default_rules); 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
4af4662f MZ	48	/* Without LSM specific knowledge, the default policy can only be
	49	* written in terms of .action, .func, .mask, .fsmagic, and .uid
	50	*/
3323eec9 MZ	51	static struct ima_measure_rule_entry default_rules[] = {
	52	{.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,
	53	.flags = IMA_FSMAGIC},
	54	{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
	55	{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
	56	{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
	57	{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,
	58	.flags = IMA_FSMAGIC},
	59	{.action = DONT_MEASURE,.fsmagic = 0xF97CFF8C,.flags = IMA_FSMAGIC},
	60	{.action = MEASURE,.func = FILE_MMAP,.mask = MAY_EXEC,
	61	.flags = IMA_FUNC \| IMA_MASK},
	62	{.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
	63	.flags = IMA_FUNC \| IMA_MASK},
	64	{.action = MEASURE,.func = PATH_CHECK,.mask = MAY_READ,.uid = 0,
	65	.flags = IMA_FUNC \| IMA_MASK \| IMA_UID}
	66	};
	67
	68	static LIST_HEAD(measure_default_rules);
4af4662f	69	static LIST_HEAD(measure_policy_rules);
3323eec9 MZ	70	static struct list_head *ima_measure;
3323eec9 MZ	71
4af4662f MZ	72	static DEFINE_MUTEX(ima_measure_mutex);
4af4662f MZ	73
3323eec9 MZ	74	/**
	75	* ima_match_rules - determine whether an inode matches the measure rule.
	76	* @rule: a pointer to a rule
	77	* @inode: a pointer to an inode
	78	* @func: LIM hook identifier
	79	* @mask: requested action (MAY_READ \| MAY_WRITE \| MAY_APPEND \| MAY_EXEC)
	80	*
	81	* Returns true on rule match, false on failure.
	82	*/
	83	static bool ima_match_rules(struct ima_measure_rule_entry *rule,
	84	struct inode *inode, enum ima_hooks func, int mask)
	85	{
	86	struct task_struct *tsk = current;
4af4662f	87	int i;
3323eec9 MZ	88
	89	if ((rule->flags & IMA_FUNC) && rule->func != func)
	90	return false;
	91	if ((rule->flags & IMA_MASK) && rule->mask != mask)
	92	return false;
	93	if ((rule->flags & IMA_FSMAGIC)
	94	&& rule->fsmagic != inode->i_sb->s_magic)
	95	return false;
	96	if ((rule->flags & IMA_UID) && rule->uid != tsk->cred->uid)
	97	return false;
4af4662f MZ	98	for (i = 0; i < MAX_LSM_RULES; i++) {
	99	int rc;
	100	u32 osid, sid;
	101
	102	if (!rule->lsm[i].rule)
	103	continue;
	104
	105	switch (i) {
	106	case LSM_OBJ_USER:
	107	case LSM_OBJ_ROLE:
	108	case LSM_OBJ_TYPE:
	109	security_inode_getsecid(inode, &osid);
	110	rc = security_filter_rule_match(osid,
	111	rule->lsm[i].type,
	112	AUDIT_EQUAL,
	113	rule->lsm[i].rule,
	114	NULL);
	115	break;
	116	case LSM_SUBJ_USER:
	117	case LSM_SUBJ_ROLE:
	118	case LSM_SUBJ_TYPE:
	119	security_task_getsecid(tsk, &sid);
	120	rc = security_filter_rule_match(sid,
	121	rule->lsm[i].type,
	122	AUDIT_EQUAL,
	123	rule->lsm[i].rule,
	124	NULL);
	125	default:
	126	break;
	127	}
	128	if (!rc)
	129	return false;
	130	}
3323eec9 MZ	131	return true;
	132	}
	133
	134	/**
	135	* ima_match_policy - decision based on LSM and other conditions
	136	* @inode: pointer to an inode for which the policy decision is being made
	137	* @func: IMA hook identifier
	138	* @mask: requested action (MAY_READ \| MAY_WRITE \| MAY_APPEND \| MAY_EXEC)
	139	*
	140	* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
	141	* conditions.
	142	*
	143	* (There is no need for locking when walking the policy list,
	144	* as elements in the list are never deleted, nor does the list
	145	* change.)
	146	*/
	147	int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
	148	{
	149	struct ima_measure_rule_entry *entry;
	150
	151	list_for_each_entry(entry, ima_measure, list) {
	152	bool rc;
	153
	154	rc = ima_match_rules(entry, inode, func, mask);
	155	if (rc)
	156	return entry->action;
	157	}
	158	return 0;
	159	}
	160
	161	/**
	162	* ima_init_policy - initialize the default measure rules.
	163	*
3323eec9	164	* ima_measure points to either the measure_default_rules or the
4af4662f	165	* the new measure_policy_rules.
3323eec9 MZ	166	*/
	167	void ima_init_policy(void)
	168	{
	169	int i;
	170
	171	for (i = 0; i < ARRAY_SIZE(default_rules); i++)
	172	list_add_tail(&default_rules[i].list, &measure_default_rules);
	173	ima_measure = &measure_default_rules;
	174	}
4af4662f MZ	175
	176	/**
	177	* ima_update_policy - update default_rules with new measure rules
	178	*
	179	* Called on file .release to update the default rules with a complete new
	180	* policy. Once updated, the policy is locked, no additional rules can be
	181	* added to the policy.
	182	*/
	183	void ima_update_policy(void)
	184	{
	185	const char *op = "policy_update";
	186	const char *cause = "already exists";
	187	int result = 1;
	188	int audit_info = 0;
	189
	190	if (ima_measure == &measure_default_rules) {
	191	ima_measure = &measure_policy_rules;
	192	cause = "complete";
	193	result = 0;
	194	}
	195	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	196	NULL, op, cause, result, audit_info);
	197	}
	198
	199	enum {
	200	Opt_err = -1,
	201	Opt_measure = 1, Opt_dont_measure,
	202	Opt_obj_user, Opt_obj_role, Opt_obj_type,
	203	Opt_subj_user, Opt_subj_role, Opt_subj_type,
	204	Opt_func, Opt_mask, Opt_fsmagic, Opt_uid
	205	};
	206
	207	static match_table_t policy_tokens = {
	208	{Opt_measure, "measure"},
	209	{Opt_dont_measure, "dont_measure"},
	210	{Opt_obj_user, "obj_user=%s"},
	211	{Opt_obj_role, "obj_role=%s"},
	212	{Opt_obj_type, "obj_type=%s"},
	213	{Opt_subj_user, "subj_user=%s"},
	214	{Opt_subj_role, "subj_role=%s"},
	215	{Opt_subj_type, "subj_type=%s"},
	216	{Opt_func, "func=%s"},
	217	{Opt_mask, "mask=%s"},
	218	{Opt_fsmagic, "fsmagic=%s"},
	219	{Opt_uid, "uid=%s"},
	220	{Opt_err, NULL}
	221	};
	222
	223	static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
	224	char *args, int lsm_rule, int audit_type)
	225	{
	226	int result;
	227
	228	entry->lsm[lsm_rule].type = audit_type;
	229	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
	230	AUDIT_EQUAL, args,
	231	&entry->lsm[lsm_rule].rule);
	232	return result;
	233	}
	234
	235	static int ima_parse_rule(char rule, struct ima_measure_rule_entry entry)
	236	{
	237	struct audit_buffer *ab;
	238	char *p;
239	int result = 0;
240
523979ad	241	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
4af4662f MZ	242
	243	entry->action = -1;
	244	while ((p = strsep(&rule, " \n")) != NULL) {
	245	substring_t args[MAX_OPT_ARGS];
	246	int token;
	247	unsigned long lnum;
	248
	249	if (result < 0)
	250	break;
	251	if (!*p)
	252	continue;
	253	token = match_token(p, policy_tokens, args);
	254	switch (token) {
	255	case Opt_measure:
	256	audit_log_format(ab, "%s ", "measure");
	257	entry->action = MEASURE;
	258	break;
	259	case Opt_dont_measure:
	260	audit_log_format(ab, "%s ", "dont_measure");
	261	entry->action = DONT_MEASURE;
	262	break;
	263	case Opt_func:
	264	audit_log_format(ab, "func=%s ", args[0].from);
	265	if (strcmp(args[0].from, "PATH_CHECK") == 0)
	266	entry->func = PATH_CHECK;
	267	else if (strcmp(args[0].from, "FILE_MMAP") == 0)
	268	entry->func = FILE_MMAP;
	269	else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
	270	entry->func = BPRM_CHECK;
	271	else
	272	result = -EINVAL;
	273	if (!result)
	274	entry->flags \|= IMA_FUNC;
	275	break;
	276	case Opt_mask:
	277	audit_log_format(ab, "mask=%s ", args[0].from);
	278	if ((strcmp(args[0].from, "MAY_EXEC")) == 0)
	279	entry->mask = MAY_EXEC;
	280	else if (strcmp(args[0].from, "MAY_WRITE") == 0)
	281	entry->mask = MAY_WRITE;
	282	else if (strcmp(args[0].from, "MAY_READ") == 0)
	283	entry->mask = MAY_READ;
	284	else if (strcmp(args[0].from, "MAY_APPEND") == 0)
	285	entry->mask = MAY_APPEND;
	286	else
	287	result = -EINVAL;
	288	if (!result)
	289	entry->flags \|= IMA_MASK;
	290	break;
	291	case Opt_fsmagic:
	292	audit_log_format(ab, "fsmagic=%s ", args[0].from);
	293	result = strict_strtoul(args[0].from, 16,
	294	&entry->fsmagic);
	295	if (!result)
	296	entry->flags \|= IMA_FSMAGIC;
	297	break;
	298	case Opt_uid:
	299	audit_log_format(ab, "uid=%s ", args[0].from);
	300	result = strict_strtoul(args[0].from, 10, &lnum);
	301	if (!result) {
	302	entry->uid = (uid_t) lnum;
	303	if (entry->uid != lnum)
	304	result = -EINVAL;
	305	else
306	entry->flags \|= IMA_UID;
307	}
308	break;
309	case Opt_obj_user:
310	audit_log_format(ab, "obj_user=%s ", args[0].from);
311	result = ima_lsm_rule_init(entry, args[0].from,
312	LSM_OBJ_USER,
313	AUDIT_OBJ_USER);
314	break;
315	case Opt_obj_role:
316	audit_log_format(ab, "obj_role=%s ", args[0].from);
317	result = ima_lsm_rule_init(entry, args[0].from,
318	LSM_OBJ_ROLE,
319	AUDIT_OBJ_ROLE);
320	break;
321	case Opt_obj_type:
322	audit_log_format(ab, "obj_type=%s ", args[0].from);
323	result = ima_lsm_rule_init(entry, args[0].from,
324	LSM_OBJ_TYPE,
325	AUDIT_OBJ_TYPE);
326	break;
327	case Opt_subj_user:
328	audit_log_format(ab, "subj_user=%s ", args[0].from);
329	result = ima_lsm_rule_init(entry, args[0].from,
330	LSM_SUBJ_USER,
331	AUDIT_SUBJ_USER);
332	break;
333	case Opt_subj_role:
334	audit_log_format(ab, "subj_role=%s ", args[0].from);
335	result = ima_lsm_rule_init(entry, args[0].from,
336	LSM_SUBJ_ROLE,
337	AUDIT_SUBJ_ROLE);
338	break;
339	case Opt_subj_type:
340	audit_log_format(ab, "subj_type=%s ", args[0].from);
341	result = ima_lsm_rule_init(entry, args[0].from,
342	LSM_SUBJ_TYPE,
343	AUDIT_SUBJ_TYPE);
344	break;
345	case Opt_err:
523979ad	346	audit_log_format(ab, "UNKNOWN=%s ", p);
4af4662f MZ	347	break;
	348	}
	349	}
	350	if (entry->action == UNKNOWN)
	351	result = -EINVAL;
	352
523979ad	353	audit_log_format(ab, "res=%d", !result ? 0 : 1);
4af4662f MZ	354	audit_log_end(ab);
	355	return result;
	356	}
	357
	358	/**
	359	* ima_parse_add_rule - add a rule to measure_policy_rules
	360	* @rule - ima measurement policy rule
	361	*
	362	* Uses a mutex to protect the policy list from multiple concurrent writers.
	363	* Returns 0 on success, an error code on failure.
	364	*/
	365	int ima_parse_add_rule(char *rule)
	366	{
523979ad	367	const char *op = "update_policy";
4af4662f MZ	368	struct ima_measure_rule_entry *entry;
	369	int result = 0;
	370	int audit_info = 0;
	371
	372	/* Prevent installed policy from changing */
	373	if (ima_measure != &measure_default_rules) {
	374	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	375	NULL, op, "already exists",
	376	-EACCES, audit_info);
	377	return -EACCES;
	378	}
	379
	380	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
	381	if (!entry) {
	382	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	383	NULL, op, "-ENOMEM", -ENOMEM, audit_info);
	384	return -ENOMEM;
	385	}
	386
	387	INIT_LIST_HEAD(&entry->list);
	388
	389	result = ima_parse_rule(rule, entry);
	390	if (!result) {
	391	mutex_lock(&ima_measure_mutex);
	392	list_add_tail(&entry->list, &measure_policy_rules);
	393	mutex_unlock(&ima_measure_mutex);
523979ad	394	} else {
4af4662f	395	kfree(entry);
523979ad MZ	396	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
	397	NULL, op, "invalid policy", result,
	398	audit_info);
	399	}
4af4662f MZ	400	return result;
	401	}
	402
	403	/* ima_delete_rules called to cleanup invalid policy */
64c61d80	404	void ima_delete_rules(void)
4af4662f MZ	405	{
	406	struct ima_measure_rule_entry entry, tmp;
	407
	408	mutex_lock(&ima_measure_mutex);
	409	list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) {
	410	list_del(&entry->list);
	411	kfree(entry);
	412	}
	413	mutex_unlock(&ima_measure_mutex);
	414	}