/* * Copyright (C) 2008 IBM Corporation * Author: Mimi Zohar * * 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 #include #include #include #include #include #include #include #include #include "ima.h" /* flags definitions */ #define IMA_FUNC 0x0001 #define IMA_MASK 0x0002 #define IMA_FSMAGIC 0x0004 #define IMA_UID 0x0008 #define IMA_FOWNER 0x0010 #define IMA_FSUUID 0x0020 #define IMA_INMASK 0x0040 #define IMA_EUID 0x0080 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ #define DONT_MEASURE 0x0002 #define APPRAISE 0x0004 /* same as IMA_APPRAISE */ #define DONT_APPRAISE 0x0008 #define AUDIT 0x0040 int ima_policy_flag; static int temp_ima_appraise; #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 }; enum policy_types { ORIGINAL_TCB = 1, DEFAULT_TCB }; struct ima_rule_entry { struct list_head list; int action; unsigned int flags; enum ima_hooks func; int mask; unsigned long fsmagic; u8 fsuuid[16]; kuid_t uid; kuid_t fowner; struct { void *rule; /* LSM file metadata specific */ void *args_p; /* audit value */ 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, .uid, and .fowner */ /* * 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_rule_entry dont_measure_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 = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC} }; static struct ima_rule_entry original_measurement_rules[] = { {.action = MEASURE, .func = MMAP_CHECK, .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 = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_MASK | IMA_UID}, {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC}, {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC}, }; static struct ima_rule_entry default_measurement_rules[] = { {.action = MEASURE, .func = MMAP_CHECK, .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 = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_EUID}, {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, .uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_UID}, {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC}, {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC}, }; static struct ima_rule_entry default_appraise_rules[] = { {.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = RAMFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC}, #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .flags = IMA_FOWNER}, #else /* force signature */ {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .flags = IMA_FOWNER | IMA_DIGSIG_REQUIRED}, #endif }; static LIST_HEAD(ima_default_rules); static LIST_HEAD(ima_policy_rules); static LIST_HEAD(ima_temp_rules); static struct list_head *ima_rules; static int ima_policy __initdata; static int __init default_measure_policy_setup(char *str) { if (ima_policy) return 1; ima_policy = ORIGINAL_TCB; return 1; } __setup("ima_tcb", default_measure_policy_setup); static int __init policy_setup(char *str) { if (ima_policy) return 1; if (strcmp(str, "tcb") == 0) ima_policy = DEFAULT_TCB; return 1; } __setup("ima_policy=", policy_setup); static bool ima_use_appraise_tcb __initdata; static int __init default_appraise_policy_setup(char *str) { ima_use_appraise_tcb = 1; return 1; } __setup("ima_appraise_tcb", default_appraise_policy_setup); /* * The LSM policy can be reloaded, leaving the IMA LSM based rules referring * to the old, stale LSM policy. Update the IMA LSM based rules to reflect * the reloaded LSM policy. We assume the rules still exist; and BUG_ON() if * they don't. */ static void ima_lsm_update_rules(void) { struct ima_rule_entry *entry; int result; int i; list_for_each_entry(entry, &ima_policy_rules, list) { for (i = 0; i < MAX_LSM_RULES; i++) { if (!entry->lsm[i].rule) continue; result = security_filter_rule_init(entry->lsm[i].type, Audit_equal, entry->lsm[i].args_p, &entry->lsm[i].rule); BUG_ON(!entry->lsm[i].rule); } } } /** * 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_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 && func != POST_SETATTR)) return false; if ((rule->flags & IMA_MASK) && (rule->mask != mask && func != POST_SETATTR)) return false; if ((rule->flags & IMA_INMASK) && (!(rule->mask & mask) && func != POST_SETATTR)) return false; if ((rule->flags & IMA_FSMAGIC) && rule->fsmagic != inode->i_sb->s_magic) return false; if ((rule->flags & IMA_FSUUID) && memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid))) return false; if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid)) return false; if (rule->flags & IMA_EUID) { if (has_capability_noaudit(current, CAP_SETUID)) { if (!uid_eq(rule->uid, cred->euid) && !uid_eq(rule->uid, cred->suid) && !uid_eq(rule->uid, cred->uid)) return false; } else if (!uid_eq(rule->uid, cred->euid)) return false; } if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid)) return false; for (i = 0; i < MAX_LSM_RULES; i++) { int rc = 0; u32 osid, sid; int retried = 0; if (!rule->lsm[i].rule) continue; retry: 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 < 0) && (!retried)) { retried = 1; ima_lsm_update_rules(); goto retry; } if (!rc) return false; } return true; } /* * In addition to knowing that we need to appraise the file in general, * we need to differentiate between calling hooks, for hook specific rules. */ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) { if (!(rule->flags & IMA_FUNC)) return IMA_FILE_APPRAISE; switch (func) { case MMAP_CHECK: return IMA_MMAP_APPRAISE; case BPRM_CHECK: return IMA_BPRM_APPRAISE; case MODULE_CHECK: return IMA_MODULE_APPRAISE; case FIRMWARE_CHECK: return IMA_FIRMWARE_APPRAISE; case FILE_CHECK: default: return IMA_FILE_APPRAISE; } } /** * 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. * * Since the IMA policy may be updated multiple times we need to lock the * list when walking it. Reads are many orders of magnitude more numerous * than writes so ima_match_policy() is classical RCU candidate. */ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, int flags) { struct ima_rule_entry *entry; int action = 0, actmask = flags | (flags << 1); rcu_read_lock(); list_for_each_entry_rcu(entry, ima_rules, list) { if (!(entry->action & actmask)) continue; if (!ima_match_rules(entry, inode, func, mask)) continue; action |= entry->flags & IMA_ACTION_FLAGS; action |= entry->action & IMA_DO_MASK; if (entry->action & IMA_APPRAISE) action |= get_subaction(entry, func); if (entry->action & IMA_DO_MASK) actmask &= ~(entry->action | entry->action << 1); else actmask &= ~(entry->action | entry->action >> 1); if (!actmask) break; } rcu_read_unlock(); return action; } /* * Initialize the ima_policy_flag variable based on the currently * loaded policy. Based on this flag, the decision to short circuit * out of a function or not call the function in the first place * can be made earlier. */ void ima_update_policy_flag(void) { struct ima_rule_entry *entry; list_for_each_entry(entry, ima_rules, list) { if (entry->action & IMA_DO_MASK) ima_policy_flag |= entry->action; } ima_appraise |= temp_ima_appraise; if (!ima_appraise) ima_policy_flag &= ~IMA_APPRAISE; } /** * ima_init_policy - initialize the default measure rules. * * ima_rules points to either the ima_default_rules or the * the new ima_policy_rules. */ void __init ima_init_policy(void) { int i, measure_entries, appraise_entries; /* if !ima_policy set entries = 0 so we load NO default rules */ measure_entries = ima_policy ? ARRAY_SIZE(dont_measure_rules) : 0; appraise_entries = ima_use_appraise_tcb ? ARRAY_SIZE(default_appraise_rules) : 0; for (i = 0; i < measure_entries; i++) list_add_tail(&dont_measure_rules[i].list, &ima_default_rules); switch (ima_policy) { case ORIGINAL_TCB: for (i = 0; i < ARRAY_SIZE(original_measurement_rules); i++) list_add_tail(&original_measurement_rules[i].list, &ima_default_rules); break; case DEFAULT_TCB: for (i = 0; i < ARRAY_SIZE(default_measurement_rules); i++) list_add_tail(&default_measurement_rules[i].list, &ima_default_rules); default: break; } for (i = 0; i < appraise_entries; i++) { list_add_tail(&default_appraise_rules[i].list, &ima_default_rules); } ima_rules = &ima_default_rules; } /* Make sure we have a valid policy, at least containing some rules. */ int ima_check_policy(void) { if (list_empty(&ima_temp_rules)) return -EINVAL; return 0; } /** * ima_update_policy - update default_rules with new measure rules * * Called on file .release to update the default rules with a complete new * policy. What we do here is to splice ima_policy_rules and ima_temp_rules so * they make a queue. The policy may be updated multiple times and this is the * RCU updater. * * Policy rules are never deleted so ima_policy_flag gets zeroed only once when * we switch from the default policy to user defined. */ void ima_update_policy(void) { struct list_head *first, *last, *policy; /* append current policy with the new rules */ first = (&ima_temp_rules)->next; last = (&ima_temp_rules)->prev; policy = &ima_policy_rules; synchronize_rcu(); last->next = policy; rcu_assign_pointer(list_next_rcu(policy->prev), first); first->prev = policy->prev; policy->prev = last; /* prepare for the next policy rules addition */ INIT_LIST_HEAD(&ima_temp_rules); if (ima_rules != policy) { ima_policy_flag = 0; ima_rules = policy; } ima_update_policy_flag(); } enum { Opt_err = -1, Opt_measure = 1, Opt_dont_measure, Opt_appraise, Opt_dont_appraise, Opt_audit, 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_fsuuid, Opt_uid, Opt_euid, Opt_fowner, Opt_appraise_type, Opt_permit_directio }; static match_table_t policy_tokens = { {Opt_measure, "measure"}, {Opt_dont_measure, "dont_measure"}, {Opt_appraise, "appraise"}, {Opt_dont_appraise, "dont_appraise"}, {Opt_audit, "audit"}, {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_fsuuid, "fsuuid=%s"}, {Opt_uid, "uid=%s"}, {Opt_euid, "euid=%s"}, {Opt_fowner, "fowner=%s"}, {Opt_appraise_type, "appraise_type=%s"}, {Opt_permit_directio, "permit_directio"}, {Opt_err, NULL} }; static int ima_lsm_rule_init(struct ima_rule_entry *entry, substring_t *args, int lsm_rule, int audit_type) { int result; if (entry->lsm[lsm_rule].rule) return -EINVAL; entry->lsm[lsm_rule].args_p = match_strdup(args); if (!entry->lsm[lsm_rule].args_p) return -ENOMEM; entry->lsm[lsm_rule].type = audit_type; result = security_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal, entry->lsm[lsm_rule].args_p, &entry->lsm[lsm_rule].rule); if (!entry->lsm[lsm_rule].rule) { kfree(entry->lsm[lsm_rule].args_p); 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_rule_entry *entry) { struct audit_buffer *ab; char *from; char *p; int result = 0; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE); entry->uid = INVALID_UID; entry->fowner = INVALID_UID; 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_appraise: ima_log_string(ab, "action", "appraise"); if (entry->action != UNKNOWN) result = -EINVAL; entry->action = APPRAISE; break; case Opt_dont_appraise: ima_log_string(ab, "action", "dont_appraise"); if (entry->action != UNKNOWN) result = -EINVAL; entry->action = DONT_APPRAISE; break; case Opt_audit: ima_log_string(ab, "action", "audit"); if (entry->action != UNKNOWN) result = -EINVAL; entry->action = AUDIT; 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, "MODULE_CHECK") == 0) entry->func = MODULE_CHECK; else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0) entry->func = FIRMWARE_CHECK; else if ((strcmp(args[0].from, "FILE_MMAP") == 0) || (strcmp(args[0].from, "MMAP_CHECK") == 0)) entry->func = MMAP_CHECK; 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; from = args[0].from; if (*from == '^') from++; if ((strcmp(from, "MAY_EXEC")) == 0) entry->mask = MAY_EXEC; else if (strcmp(from, "MAY_WRITE") == 0) entry->mask = MAY_WRITE; else if (strcmp(from, "MAY_READ") == 0) entry->mask = MAY_READ; else if (strcmp(from, "MAY_APPEND") == 0) entry->mask = MAY_APPEND; else result = -EINVAL; if (!result) entry->flags |= (*args[0].from == '^') ? IMA_INMASK : IMA_MASK; break; case Opt_fsmagic: ima_log_string(ab, "fsmagic", args[0].from); if (entry->fsmagic) { result = -EINVAL; break; } result = kstrtoul(args[0].from, 16, &entry->fsmagic); if (!result) entry->flags |= IMA_FSMAGIC; break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); if (memchr_inv(entry->fsuuid, 0x00, sizeof(entry->fsuuid))) { result = -EINVAL; break; } result = blk_part_pack_uuid(args[0].from, entry->fsuuid); if (!result) entry->flags |= IMA_FSUUID; break; case Opt_uid: ima_log_string(ab, "uid", args[0].from); case Opt_euid: if (token == Opt_euid) ima_log_string(ab, "euid", args[0].from); if (uid_valid(entry->uid)) { result = -EINVAL; break; } result = kstrtoul(args[0].from, 10, &lnum); if (!result) { entry->uid = make_kuid(current_user_ns(), (uid_t) lnum); if (!uid_valid(entry->uid) || (uid_t)lnum != lnum) result = -EINVAL; else entry->flags |= (token == Opt_uid) ? IMA_UID : IMA_EUID; } break; case Opt_fowner: ima_log_string(ab, "fowner", args[0].from); if (uid_valid(entry->fowner)) { result = -EINVAL; break; } result = kstrtoul(args[0].from, 10, &lnum); if (!result) { entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum); if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum)) result = -EINVAL; else entry->flags |= IMA_FOWNER; } break; case Opt_obj_user: ima_log_string(ab, "obj_user", args[0].from); result = ima_lsm_rule_init(entry, args, 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, 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, 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, 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, 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, LSM_SUBJ_TYPE, AUDIT_SUBJ_TYPE); break; case Opt_appraise_type: if (entry->action != APPRAISE) { result = -EINVAL; break; } ima_log_string(ab, "appraise_type", args[0].from); if ((strcmp(args[0].from, "imasig")) == 0) entry->flags |= IMA_DIGSIG_REQUIRED; else result = -EINVAL; break; case Opt_permit_directio: entry->flags |= IMA_PERMIT_DIRECTIO; break; case Opt_err: ima_log_string(ab, "UNKNOWN", p); result = -EINVAL; break; } } if (!result && (entry->action == UNKNOWN)) result = -EINVAL; else if (entry->func == MODULE_CHECK) temp_ima_appraise |= IMA_APPRAISE_MODULES; else if (entry->func == FIRMWARE_CHECK) temp_ima_appraise |= IMA_APPRAISE_FIRMWARE; audit_log_format(ab, "res=%d", !result); audit_log_end(ab); return result; } /** * ima_parse_add_rule - add a rule to ima_policy_rules * @rule - ima measurement policy rule * * Avoid locking by allowing just one writer at a time in ima_write_policy() * Returns the length of the rule parsed, an error code on failure */ ssize_t ima_parse_add_rule(char *rule) { static const char op[] = "update_policy"; char *p; struct ima_rule_entry *entry; ssize_t result, len; int audit_info = 0; p = strsep(&rule, "\n"); len = strlen(p) + 1; p += strspn(p, " \t"); if (*p == '#' || *p == '\0') return len; 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(p, entry); if (result) { kfree(entry); integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, op, "invalid-policy", result, audit_info); return result; } list_add_tail(&entry->list, &ima_temp_rules); return len; } /** * ima_delete_rules() called to cleanup invalid in-flight policy. * We don't need locking as we operate on the temp list, which is * different from the active one. There is also only one user of * ima_delete_rules() at a time. */ void ima_delete_rules(void) { struct ima_rule_entry *entry, *tmp; int i; temp_ima_appraise = 0; list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) { for (i = 0; i < MAX_LSM_RULES; i++) kfree(entry->lsm[i].args_p); list_del(&entry->list); kfree(entry); } } #ifdef CONFIG_IMA_READ_POLICY enum { mask_exec = 0, mask_write, mask_read, mask_append }; static char *mask_tokens[] = { "MAY_EXEC", "MAY_WRITE", "MAY_READ", "MAY_APPEND" }; enum { func_file = 0, func_mmap, func_bprm, func_module, func_firmware, func_post }; static char *func_tokens[] = { "FILE_CHECK", "MMAP_CHECK", "BPRM_CHECK", "MODULE_CHECK", "FIRMWARE_CHECK", "POST_SETATTR" }; void *ima_policy_start(struct seq_file *m, loff_t *pos) { loff_t l = *pos; struct ima_rule_entry *entry; rcu_read_lock(); list_for_each_entry_rcu(entry, ima_rules, list) { if (!l--) { rcu_read_unlock(); return entry; } } rcu_read_unlock(); return NULL; } void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos) { struct ima_rule_entry *entry = v; rcu_read_lock(); entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list); rcu_read_unlock(); (*pos)++; return (&entry->list == ima_rules) ? NULL : entry; } void ima_policy_stop(struct seq_file *m, void *v) { } #define pt(token) policy_tokens[token + Opt_err].pattern #define mt(token) mask_tokens[token] #define ft(token) func_tokens[token] /* * policy_func_show - display the ima_hooks policy rule */ static void policy_func_show(struct seq_file *m, enum ima_hooks func) { char tbuf[64] = {0,}; switch (func) { case FILE_CHECK: seq_printf(m, pt(Opt_func), ft(func_file)); break; case MMAP_CHECK: seq_printf(m, pt(Opt_func), ft(func_mmap)); break; case BPRM_CHECK: seq_printf(m, pt(Opt_func), ft(func_bprm)); break; case MODULE_CHECK: seq_printf(m, pt(Opt_func), ft(func_module)); break; case FIRMWARE_CHECK: seq_printf(m, pt(Opt_func), ft(func_firmware)); break; case POST_SETATTR: seq_printf(m, pt(Opt_func), ft(func_post)); break; default: snprintf(tbuf, sizeof(tbuf), "%d", func); seq_printf(m, pt(Opt_func), tbuf); break; } seq_puts(m, " "); } int ima_policy_show(struct seq_file *m, void *v) { struct ima_rule_entry *entry = v; int i = 0; char tbuf[64] = {0,}; rcu_read_lock(); if (entry->action & MEASURE) seq_puts(m, pt(Opt_measure)); if (entry->action & DONT_MEASURE) seq_puts(m, pt(Opt_dont_measure)); if (entry->action & APPRAISE) seq_puts(m, pt(Opt_appraise)); if (entry->action & DONT_APPRAISE) seq_puts(m, pt(Opt_dont_appraise)); if (entry->action & AUDIT) seq_puts(m, pt(Opt_audit)); seq_puts(m, " "); if (entry->flags & IMA_FUNC) policy_func_show(m, entry->func); if (entry->flags & IMA_MASK) { if (entry->mask & MAY_EXEC) seq_printf(m, pt(Opt_mask), mt(mask_exec)); if (entry->mask & MAY_WRITE) seq_printf(m, pt(Opt_mask), mt(mask_write)); if (entry->mask & MAY_READ) seq_printf(m, pt(Opt_mask), mt(mask_read)); if (entry->mask & MAY_APPEND) seq_printf(m, pt(Opt_mask), mt(mask_append)); seq_puts(m, " "); } if (entry->flags & IMA_FSMAGIC) { snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic); seq_printf(m, pt(Opt_fsmagic), tbuf); seq_puts(m, " "); } if (entry->flags & IMA_FSUUID) { seq_puts(m, "fsuuid="); for (i = 0; i < ARRAY_SIZE(entry->fsuuid); ++i) { switch (i) { case 4: case 6: case 8: case 10: seq_puts(m, "-"); } seq_printf(m, "%x", entry->fsuuid[i]); } seq_puts(m, " "); } if (entry->flags & IMA_UID) { snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid)); seq_printf(m, pt(Opt_uid), tbuf); seq_puts(m, " "); } if (entry->flags & IMA_EUID) { snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid)); seq_printf(m, pt(Opt_euid), tbuf); seq_puts(m, " "); } if (entry->flags & IMA_FOWNER) { snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner)); seq_printf(m, pt(Opt_fowner), tbuf); seq_puts(m, " "); } for (i = 0; i < MAX_LSM_RULES; i++) { if (entry->lsm[i].rule) { switch (i) { case LSM_OBJ_USER: seq_printf(m, pt(Opt_obj_user), (char *)entry->lsm[i].args_p); break; case LSM_OBJ_ROLE: seq_printf(m, pt(Opt_obj_role), (char *)entry->lsm[i].args_p); break; case LSM_OBJ_TYPE: seq_printf(m, pt(Opt_obj_type), (char *)entry->lsm[i].args_p); break; case LSM_SUBJ_USER: seq_printf(m, pt(Opt_subj_user), (char *)entry->lsm[i].args_p); break; case LSM_SUBJ_ROLE: seq_printf(m, pt(Opt_subj_role), (char *)entry->lsm[i].args_p); break; case LSM_SUBJ_TYPE: seq_printf(m, pt(Opt_subj_type), (char *)entry->lsm[i].args_p); break; } } } if (entry->flags & IMA_DIGSIG_REQUIRED) seq_puts(m, "appraise_type=imasig "); if (entry->flags & IMA_PERMIT_DIRECTIO) seq_puts(m, "permit_directio "); rcu_read_unlock(); seq_puts(m, "\n"); return 0; } #endif /* CONFIG_IMA_READ_POLICY */