diff options
Diffstat (limited to 'security/integrity/ima/ima_policy.c')
-rw-r--r-- | security/integrity/ima/ima_policy.c | 107 |
1 files changed, 79 insertions, 28 deletions
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 8643a93c596..aef8c0a923a 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -246,6 +246,9 @@ static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry, { 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, @@ -253,6 +256,13 @@ static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry, 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; @@ -261,28 +271,41 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE); - entry->action = -1; - while ((p = strsep(&rule, " \n")) != NULL) { + 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) + if ((*p == '\0') || (*p == ' ') || (*p == '\t')) continue; token = match_token(p, policy_tokens, args); switch (token) { case Opt_measure: - audit_log_format(ab, "%s ", "measure"); + ima_log_string(ab, "action", "measure"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + entry->action = MEASURE; break; case Opt_dont_measure: - audit_log_format(ab, "%s ", "dont_measure"); + ima_log_string(ab, "action", "dont_measure"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + entry->action = DONT_MEASURE; break; case Opt_func: - audit_log_format(ab, "func=%s ", args[0].from); + 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 */ @@ -298,7 +321,11 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) entry->flags |= IMA_FUNC; break; case Opt_mask: - audit_log_format(ab, "mask=%s ", args[0].from); + 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) @@ -313,14 +340,26 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) entry->flags |= IMA_MASK; break; case Opt_fsmagic: - audit_log_format(ab, "fsmagic=%s ", args[0].from); + 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: - audit_log_format(ab, "uid=%s ", args[0].from); + 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; @@ -331,50 +370,51 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) } break; case Opt_obj_user: - audit_log_format(ab, "obj_user=%s ", args[0].from); + 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: - audit_log_format(ab, "obj_role=%s ", args[0].from); + 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: - audit_log_format(ab, "obj_type=%s ", args[0].from); + 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: - audit_log_format(ab, "subj_user=%s ", args[0].from); + 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: - audit_log_format(ab, "subj_role=%s ", args[0].from); + 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: - audit_log_format(ab, "subj_type=%s ", args[0].from); + 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: - audit_log_format(ab, "UNKNOWN=%s ", p); + ima_log_string(ab, "UNKNOWN", p); + result = -EINVAL; break; } } - if (entry->action == UNKNOWN) + if (!result && (entry->action == UNKNOWN)) result = -EINVAL; - audit_log_format(ab, "res=%d", !result ? 0 : 1); + audit_log_format(ab, "res=%d", !!result); audit_log_end(ab); return result; } @@ -384,13 +424,14 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) * @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. + * Returns the length of the rule parsed, an error code on failure */ -int ima_parse_add_rule(char *rule) +ssize_t ima_parse_add_rule(char *rule) { const char *op = "update_policy"; + char *p; struct ima_measure_rule_entry *entry; - int result = 0; + ssize_t result, len; int audit_info = 0; /* Prevent installed policy from changing */ @@ -410,18 +451,28 @@ int ima_parse_add_rule(char *rule) 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 { + 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; } - 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 */ |