[PATCH v8 2/3] IMA: Call workqueue functions to measure queued keys

From: Lakshmi Ramasubramanian
Date: Wed Jan 08 2020 - 21:44:11 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 | 8 ++++++++
security/integrity/ima/ima_policy.c | 3 +++
2 files changed, 11 insertions(+)

diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c
index 1d56f003f1a7..eb71cbf224c1 100644
--- a/security/integrity/ima/ima_asymmetric_keys.c
+++ b/security/integrity/ima/ima_asymmetric_keys.c
@@ -145,6 +145,8 @@ 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 queued = false;
+
/* Only asymmetric keys are handled by this hook. */
if (key->type != &key_type_asymmetric)
return;
@@ -152,6 +154,12 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
if (!payload || (payload_len == 0))
return;

+ if (!ima_process_keys)
+ queued = ima_queue_key(keyring, payload, payload_len);
+
+ if (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 8f2ca487753b..1bdda05d963b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -807,6 +807,9 @@ void ima_update_policy(void)
kfree(arch_policy_entry);
}
ima_update_policy_flag();
+
+ /* Custom IMA policy has been loaded */
+ ima_process_queued_keys();
}

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