diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 26 |
2 files changed, 30 insertions, 2 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9b4381fee877..e438a1fca554 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1478,7 +1478,7 @@ ima_policy= [IMA] The builtin policies to load during IMA setup. - Format: "tcb | appraise_tcb" + Format: "tcb | appraise_tcb | secure_boot" The "tcb" policy measures all programs exec'd, files mmap'd for exec, and all files opened with the read @@ -1489,6 +1489,10 @@ all files owned by root. (This is the equivalent of ima_appraise_tcb.) + The "secure_boot" policy appraises the integrity + of files (eg. kexec kernel image, kernel modules, + firmware, policy, etc) based on file signatures. + ima_tcb [IMA] Deprecated. Use ima_policy= instead. Load a policy which meets the needs of the Trusted Computing Base. This means IMA will measure all diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 0ddc41389a9c..3653c86c70df 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -153,6 +153,17 @@ static struct ima_rule_entry default_appraise_rules[] __ro_after_init = { #endif }; +static struct ima_rule_entry secure_boot_rules[] __ro_after_init = { + {.action = APPRAISE, .func = MODULE_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, + {.action = APPRAISE, .func = FIRMWARE_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, + {.action = APPRAISE, .func = KEXEC_KERNEL_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, + {.action = APPRAISE, .func = POLICY_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +}; + static LIST_HEAD(ima_default_rules); static LIST_HEAD(ima_policy_rules); static LIST_HEAD(ima_temp_rules); @@ -171,6 +182,7 @@ static int __init default_measure_policy_setup(char *str) __setup("ima_tcb", default_measure_policy_setup); static bool ima_use_appraise_tcb __initdata; +static bool ima_use_secure_boot __initdata; static int __init policy_setup(char *str) { char *p; @@ -182,6 +194,8 @@ static int __init policy_setup(char *str) ima_policy = DEFAULT_TCB; else if (strcmp(p, "appraise_tcb") == 0) ima_use_appraise_tcb = 1; + else if (strcmp(p, "secure_boot") == 0) + ima_use_secure_boot = 1; } return 1; @@ -410,12 +424,14 @@ void ima_update_policy_flag(void) */ void __init ima_init_policy(void) { - int i, measure_entries, appraise_entries; + int i, measure_entries, appraise_entries, secure_boot_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; + secure_boot_entries = ima_use_secure_boot ? + ARRAY_SIZE(secure_boot_rules) : 0; for (i = 0; i < measure_entries; i++) list_add_tail(&dont_measure_rules[i].list, &ima_default_rules); @@ -434,6 +450,14 @@ void __init ima_init_policy(void) break; } + /* + * Insert the appraise rules requiring file signatures, prior to + * any other appraise rules. + */ + for (i = 0; i < secure_boot_entries; i++) + list_add_tail(&secure_boot_rules[i].list, + &ima_default_rules); + for (i = 0; i < appraise_entries; i++) { list_add_tail(&default_appraise_rules[i].list, &ima_default_rules); |