Re: [PATCH v4 08/10] IMA: Defined functions to queue and dequeue keys for measurement
flat view
From: Mimi Zohar <zohar@linux.ibm.com>
Date: 2019-11-06 22:44:54
Also in:
keyrings, linux-integrity, lkml
On Wed, 2019-11-06 at 11:01 -0800, Lakshmi Ramasubramanian wrote:
quoted hunk ↗ jump to hunk
+int ima_queue_or_process_key_for_measurement(struct key *keyring, + struct key *key) +{ + int rc = 0; + struct ima_measure_key_entry *entry = NULL; + const struct public_key *pk; + + if (key->type != &key_type_asymmetric) + return 0; + + mutex_lock(&ima_measure_keys_mutex);
Unless the key is being queued, there's no reason to take the lock.
+
+ if (ima_initialized) {ima_initialized is being set in ima_init(), before a custom policy is loaded. I would think that is too early. ima_update_policy() is called after loading a custom policy. Please see how to detect when a custom policy is loaded.
quoted hunk ↗ jump to hunk
+ /* + * keyring->description points to the name of the keyring + * (such as ".builtin_trusted_keys", ".ima", etc.) to + * which the given key is linked to. + * + * The name of the keyring is passed in the "eventname" + * parameter to process_buffer_measurement() and is set + * in the "eventname" field in ima_event_data for + * the key measurement IMA event. + * + * The name of the keyring is also passed in the "keyring" + * parameter to process_buffer_measurement() to check + * if the IMA policy is configured to measure a key linked + * to the given keyring. + */ + pk = key->payload.data[asym_crypto]; + process_buffer_measurement(pk->key, pk->keylen, + keyring->description, + KEYRING_CHECK, 0, + keyring->description);
Measuring the key should be done in ima_post_key_create_or_update() unless, it is being deferred. Please update the function name to reflect this. Mimi
quoted hunk ↗ jump to hunk
+ } else { + entry = ima_alloc_measure_key_entry(keyring, key); + if (entry != NULL) { + INIT_LIST_HEAD(&entry->list); + list_add_tail(&entry->list, &ima_measure_keys); + } else + rc = -ENOMEM; + } + + mutex_unlock(&ima_measure_keys_mutex); + + return rc; +}