[PATCH v1 2/2] IMA: Call workqueue functions to measure queued keys

From: Lakshmi Ramasubramanian
Date: Thu Dec 05 2019 - 20:29:52 EST


Measuring keys requires a custom IMA policy to be loaded.
Keys should be queued for measurement if a custom IMA policy
is not yet loaded. Keys queued for measurement, if any, should be
processed when a custom IMA policy is loaded.

This patch updates the IMA hook function ima_post_key_create_or_update()
to queue the key if a custom IMA policy has not yet been loaded.
And, ima_update_policy() function, which is called when
a custom IMA policy is loaded, is updated to process queued keys.

Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
---
security/integrity/ima/ima_asymmetric_keys.c | 9 +++++++++
security/integrity/ima/ima_policy.c | 6 ++++++
2 files changed, 15 insertions(+)

diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c
index fbdbe9c261cb..510b29d17a7b 100644
--- a/security/integrity/ima/ima_asymmetric_keys.c
+++ b/security/integrity/ima/ima_asymmetric_keys.c
@@ -155,6 +155,8 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
const void *payload, size_t payload_len,
unsigned long flags, bool create)
{
+ bool key_queued = false;
+
/* Only asymmetric keys are handled by this hook. */
if (key->type != &key_type_asymmetric)
return;
@@ -162,6 +164,13 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
if (!payload || (payload_len == 0))
return;

+ if (!ima_process_keys_for_measurement)
+ key_queued = ima_queue_key_for_measurement(keyring, payload,
+ payload_len);
+
+ if (key_queued)
+ return;
+
/*
* keyring->description points to the name of the keyring
* (such as ".builtin_trusted_keys", ".ima", etc.) to
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 73030a69d546..4dc8fb9957ac 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -808,6 +808,12 @@ void ima_update_policy(void)
kfree(arch_policy_entry);
}
ima_update_policy_flag();
+
+ /*
+ * Custom IMA policies have been setup.
+ * Process key(s) queued up for measurement now.
+ */
+ ima_process_queued_keys_for_measurement();
}

/* Keep the enumeration in sync with the policy_tokens! */
--
2.17.1