Re: [PATCH v1 2/2] IMA: Call workqueue functions to measure queued keys
From: Mimi Zohar
Date: Tue Dec 10 2019 - 20:40:40 EST
On Thu, 2019-12-05 at 17:29 -0800, Lakshmi Ramasubramanian wrote:
> 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)
> @@ -162,6 +164,13 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
> if (!payload || (payload_len == 0))
> + 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)
> + /*
> + * Custom IMA policies have been setup.
^has been loaded.
> + * Process key(s) queued up for measurement now.
The function name ima_process_queued_keys_for_measurement() provides a
clear indication that the keys will be processed. ÂWe don't comment
the obvious. ÂPlease remove the above comment.
> + */
> + ima_process_queued_keys_for_measurement();
> /* Keep the enumeration in sync with the policy_tokens! */