[PATCH 03/24] ima: require secure_boot rules in lockdown mode
From: David Howells
Date: Wed Apr 11 2018 - 12:25:11 EST
From: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Require the "secure_boot" rules, whether or not it is specified
on the boot command line, for both the builtin and custom policies
in secure boot lockdown mode.
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
security/integrity/ima/ima_policy.c | 39 ++++++++++++++++++++++++++---------
1 file changed, 29 insertions(+), 10 deletions(-)
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index d89bebf85421..da6f55c96a61 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -443,14 +443,21 @@ void ima_update_policy_flag(void)
*/
void __init ima_init_policy(void)
{
- int i, measure_entries, appraise_entries, secure_boot_entries;
+ int i;
+ int measure_entries = 0;
+ int appraise_entries = 0;
+ int secure_boot_entries = 0;
+ bool kernel_locked_down = __kernel_is_locked_down(NULL, false);
/* 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;
+ if (ima_policy)
+ measure_entries = ARRAY_SIZE(dont_measure_rules);
+
+ if (ima_use_appraise_tcb)
+ appraise_entries = ARRAY_SIZE(default_appraise_rules);
+
+ if (ima_use_secure_boot || kernel_locked_down)
+ secure_boot_entries = ARRAY_SIZE(secure_boot_rules);
for (i = 0; i < measure_entries; i++)
list_add_tail(&dont_measure_rules[i].list, &ima_default_rules);
@@ -471,11 +478,23 @@ void __init ima_init_policy(void)
/*
* Insert the appraise rules requiring file signatures, prior to
- * any other appraise rules.
+ * any other appraise rules. In secure boot lock-down mode, also
+ * require these appraise rules for custom policies.
*/
- for (i = 0; i < secure_boot_entries; i++)
- list_add_tail(&secure_boot_rules[i].list,
- &ima_default_rules);
+ for (i = 0; i < secure_boot_entries; i++) {
+ struct ima_rule_entry *entry;
+
+ /* Include for builtin policies */
+ list_add_tail(&secure_boot_rules[i].list, &ima_default_rules);
+
+ /* Include for custom policies */
+ if (kernel_locked_down) {
+ entry = kmemdup(&secure_boot_rules[i], sizeof(*entry),
+ GFP_KERNEL);
+ if (entry)
+ list_add_tail(&entry->list, &ima_policy_rules);
+ }
+ }
for (i = 0; i < appraise_entries; i++) {
list_add_tail(&default_appraise_rules[i].list,