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Diffstat (limited to 'ANDROID_3.4.5/security/integrity/ima/ima_policy.c')
-rw-r--r--ANDROID_3.4.5/security/integrity/ima/ima_policy.c493
1 files changed, 0 insertions, 493 deletions
diff --git a/ANDROID_3.4.5/security/integrity/ima/ima_policy.c b/ANDROID_3.4.5/security/integrity/ima/ima_policy.c
deleted file mode 100644
index d8edff20..00000000
--- a/ANDROID_3.4.5/security/integrity/ima/ima_policy.c
+++ /dev/null
@@ -1,493 +0,0 @@
-/*
- * 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 <linux/slab.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 = RAMFS_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 = FILE_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;
- const struct cred *cred = current_cred();
- 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 != 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 __init 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;
-
- if (entry->lsm[lsm_rule].rule)
- return -EINVAL;
-
- 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);
- if (!entry->lsm[lsm_rule].rule)
- return -EINVAL;
- return result;
-}
-
-static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
-{
- audit_log_format(ab, "%s=", key);
- audit_log_untrustedstring(ab, value);
- audit_log_format(ab, " ");
-}
-
-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->uid = -1;
- entry->action = UNKNOWN;
- while ((p = strsep(&rule, " \t")) != NULL) {
- substring_t args[MAX_OPT_ARGS];
- int token;
- unsigned long lnum;
-
- if (result < 0)
- break;
- if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
- continue;
- token = match_token(p, policy_tokens, args);
- switch (token) {
- case Opt_measure:
- ima_log_string(ab, "action", "measure");
-
- if (entry->action != UNKNOWN)
- result = -EINVAL;
-
- entry->action = MEASURE;
- break;
- case Opt_dont_measure:
- ima_log_string(ab, "action", "dont_measure");
-
- if (entry->action != UNKNOWN)
- result = -EINVAL;
-
- entry->action = DONT_MEASURE;
- break;
- case Opt_func:
- ima_log_string(ab, "func", args[0].from);
-
- if (entry->func)
- result = -EINVAL;
-
- if (strcmp(args[0].from, "FILE_CHECK") == 0)
- entry->func = FILE_CHECK;
- /* PATH_CHECK is for backwards compat */
- else if (strcmp(args[0].from, "PATH_CHECK") == 0)
- entry->func = FILE_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:
- ima_log_string(ab, "mask", args[0].from);
-
- if (entry->mask)
- result = -EINVAL;
-
- 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:
- ima_log_string(ab, "fsmagic", args[0].from);
-
- if (entry->fsmagic) {
- result = -EINVAL;
- break;
- }
-
- result = strict_strtoul(args[0].from, 16,
- &entry->fsmagic);
- if (!result)
- entry->flags |= IMA_FSMAGIC;
- break;
- case Opt_uid:
- ima_log_string(ab, "uid", args[0].from);
-
- if (entry->uid != -1) {
- result = -EINVAL;
- break;
- }
-
- 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:
- ima_log_string(ab, "obj_user", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
- LSM_OBJ_USER,
- AUDIT_OBJ_USER);
- break;
- case Opt_obj_role:
- ima_log_string(ab, "obj_role", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
- LSM_OBJ_ROLE,
- AUDIT_OBJ_ROLE);
- break;
- case Opt_obj_type:
- ima_log_string(ab, "obj_type", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
- LSM_OBJ_TYPE,
- AUDIT_OBJ_TYPE);
- break;
- case Opt_subj_user:
- ima_log_string(ab, "subj_user", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
- LSM_SUBJ_USER,
- AUDIT_SUBJ_USER);
- break;
- case Opt_subj_role:
- ima_log_string(ab, "subj_role", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
- LSM_SUBJ_ROLE,
- AUDIT_SUBJ_ROLE);
- break;
- case Opt_subj_type:
- ima_log_string(ab, "subj_type", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
- LSM_SUBJ_TYPE,
- AUDIT_SUBJ_TYPE);
- break;
- case Opt_err:
- ima_log_string(ab, "UNKNOWN", p);
- result = -EINVAL;
- break;
- }
- }
- if (!result && (entry->action == UNKNOWN))
- result = -EINVAL;
-
- audit_log_format(ab, "res=%d", !result);
- 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 the length of the rule parsed, an error code on failure
- */
-ssize_t ima_parse_add_rule(char *rule)
-{
- const char *op = "update_policy";
- char *p;
- struct ima_measure_rule_entry *entry;
- ssize_t result, len;
- 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);
-
- p = strsep(&rule, "\n");
- len = strlen(p) + 1;
-
- if (*p == '#') {
- kfree(entry);
- return len;
- }
-
- result = ima_parse_rule(p, entry);
- if (result) {
- kfree(entry);
- integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
- NULL, op, "invalid policy", result,
- audit_info);
- return result;
- }
-
- mutex_lock(&ima_measure_mutex);
- list_add_tail(&entry->list, &measure_policy_rules);
- mutex_unlock(&ima_measure_mutex);
-
- return len;
-}
-
-/* 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);
-}
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