--- zzzz-none-000/linux-3.10.107/security/integrity/ima/ima_policy.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/security/integrity/ima/ima_policy.c 2021-02-04 17:41:59.000000000 +0000 @@ -7,7 +7,7 @@ * the Free Software Foundation, version 2 of the License. * * ima_policy.c - * - initialize default measure policy rules + * - initialize default measure policy rules * */ #include @@ -21,12 +21,14 @@ #include "ima.h" /* flags definitions */ -#define IMA_FUNC 0x0001 -#define IMA_MASK 0x0002 +#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 */ @@ -35,11 +37,15 @@ #define DONT_APPRAISE 0x0008 #define AUDIT 0x0040 +int ima_policy_flag; + #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; @@ -68,36 +74,63 @@ * normal users can easily run the machine out of memory simply building * and running executables. */ -static struct ima_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 = 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 = MEASURE,.func = MMAP_CHECK,.mask = MAY_EXEC, +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, + {.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 = 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 = CGROUP_SUPER_MAGIC,.flags = IMA_FSMAGIC}, - {.action = APPRAISE,.fowner = GLOBAL_ROOT_UID,.flags = IMA_FOWNER}, + {.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); @@ -106,14 +139,29 @@ static DEFINE_MUTEX(ima_rules_mutex); -static bool ima_use_tcb __initdata; +static int ima_policy __initdata; static int __init default_measure_policy_setup(char *str) { - ima_use_tcb = 1; + 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) { @@ -122,12 +170,12 @@ } __setup("ima_appraise_tcb", default_appraise_policy_setup); -/* +/* * Although the IMA policy does not change, 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. + * 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) @@ -167,9 +215,14 @@ const struct cred *cred = current_cred(); int i; - if ((rule->flags & IMA_FUNC) && rule->func != func) + 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_MASK) && rule->mask != mask) + 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) @@ -179,6 +232,16 @@ 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++) { @@ -216,7 +279,7 @@ retried = 1; ima_lsm_update_rules(); goto retry; - } + } if (!rc) return false; } @@ -232,13 +295,15 @@ if (!(rule->flags & IMA_FUNC)) return IMA_FILE_APPRAISE; - switch(func) { + 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; @@ -290,6 +355,26 @@ 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; + + ima_policy_flag = 0; + list_for_each_entry(entry, ima_rules, list) { + if (entry->action & IMA_DO_MASK) + ima_policy_flag |= entry->action; + } + + if (!ima_appraise) + ima_policy_flag &= ~IMA_APPRAISE; +} + /** * ima_init_policy - initialize the default measure rules. * @@ -300,21 +385,31 @@ { int i, measure_entries, appraise_entries; - /* if !ima_use_tcb set entries = 0 so we load NO default rules */ - measure_entries = ima_use_tcb ? ARRAY_SIZE(default_rules) : 0; + /* 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 + appraise_entries; i++) { - if (i < measure_entries) - list_add_tail(&default_rules[i].list, - &ima_default_rules); - else { - int j = i - measure_entries; - list_add_tail(&default_appraise_rules[j].list, + 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; @@ -329,18 +424,8 @@ */ void ima_update_policy(void) { - const char *op = "policy_update"; - const char *cause = "already exists"; - int result = 1; - int audit_info = 0; - - if (ima_rules == &ima_default_rules) { - ima_rules = &ima_policy_rules; - cause = "complete"; - result = 0; - } - integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, - NULL, op, cause, result, audit_info); + ima_rules = &ima_policy_rules; + ima_update_policy_flag(); } enum { @@ -350,8 +435,9 @@ 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_uid, Opt_fowner, - Opt_appraise_type, Opt_fsuuid + Opt_func, Opt_mask, Opt_fsmagic, + Opt_uid, Opt_euid, Opt_fowner, + Opt_appraise_type, Opt_fsuuid, Opt_permit_directio }; static match_table_t policy_tokens = { @@ -371,8 +457,10 @@ {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} }; @@ -411,6 +499,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) { struct audit_buffer *ab; + char *from; char *p; int result = 0; @@ -483,6 +572,8 @@ 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; @@ -499,18 +590,23 @@ if (entry->mask) result = -EINVAL; - if ((strcmp(args[0].from, "MAY_EXEC")) == 0) + from = args[0].from; + if (*from == '^') + from++; + + if ((strcmp(from, "MAY_EXEC")) == 0) entry->mask = MAY_EXEC; - else if (strcmp(args[0].from, "MAY_WRITE") == 0) + else if (strcmp(from, "MAY_WRITE") == 0) entry->mask = MAY_WRITE; - else if (strcmp(args[0].from, "MAY_READ") == 0) + else if (strcmp(from, "MAY_READ") == 0) entry->mask = MAY_READ; - else if (strcmp(args[0].from, "MAY_APPEND") == 0) + else if (strcmp(from, "MAY_APPEND") == 0) entry->mask = MAY_APPEND; else result = -EINVAL; if (!result) - entry->flags |= IMA_MASK; + entry->flags |= (*args[0].from == '^') + ? IMA_INMASK : IMA_MASK; break; case Opt_fsmagic: ima_log_string(ab, "fsmagic", args[0].from); @@ -520,8 +616,7 @@ break; } - result = strict_strtoul(args[0].from, 16, - &entry->fsmagic); + result = kstrtoul(args[0].from, 16, &entry->fsmagic); if (!result) entry->flags |= IMA_FSMAGIC; break; @@ -541,19 +636,25 @@ 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 = strict_strtoul(args[0].from, 10, &lnum); + 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)) + entry->uid = make_kuid(current_user_ns(), + (uid_t) lnum); + if (!uid_valid(entry->uid) || + (uid_t)lnum != lnum) result = -EINVAL; else - entry->flags |= IMA_UID; + entry->flags |= (token == Opt_uid) + ? IMA_UID : IMA_EUID; } break; case Opt_fowner: @@ -564,7 +665,7 @@ break; } - result = strict_strtoul(args[0].from, 10, &lnum); + 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)) @@ -621,6 +722,9 @@ 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; @@ -631,6 +735,8 @@ result = -EINVAL; else if (entry->func == MODULE_CHECK) ima_appraise |= IMA_APPRAISE_MODULES; + else if (entry->func == FIRMWARE_CHECK) + ima_appraise |= IMA_APPRAISE_FIRMWARE; audit_log_format(ab, "res=%d", !result); audit_log_end(ab); return result; @@ -645,19 +751,18 @@ */ ssize_t ima_parse_add_rule(char *rule) { - const char *op = "update_policy"; + static const char op[] = "update_policy"; char *p; struct ima_rule_entry *entry; ssize_t result, len; int audit_info = 0; - /* Prevent installed policy from changing */ - if (ima_rules != &ima_default_rules) { - integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, - NULL, op, "already exists", - -EACCES, audit_info); - return -EACCES; - } + 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) { @@ -668,19 +773,11 @@ 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, + NULL, op, "invalid-policy", result, audit_info); return result; }