[PATCH v3 3/3] IMA: Support early boot measurement of critical data

[Lakshmi Ramasubramanian <nramas@linux.microsoft.com>]

The IMA hook ima_measure_critical_data() requires a custom IMA policy
to be loaded to determine what data should be measured by IMA.
If a custom policy is not loaded by the time ima_measure_critical_data()
is called, then IMA needs to queue the data until a policy is loaded.

Update ima_measure_critical_data() to utilize early boot measurement
support to defer processing data if a custom IMA policy is not yet
loaded.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
 security/integrity/ima/ima_main.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 438199e43f5e..5162917e6bf2 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -898,6 +898,8 @@ void ima_measure_critical_data(const char *event_name,
 			       const void *buf, int buf_len,
 			       bool measure_buf_hash)
 {
+	bool queued = false;
+
 	if (!event_name || !event_data_source || !buf || !buf_len) {
 		pr_err("Invalid arguments passed to %s().\n", __func__);
 		return;
@@ -909,6 +911,14 @@ void ima_measure_critical_data(const char *event_name,
 		return;
 	}
 
+	if (ima_should_queue_data())
+		queued = ima_queue_data(event_name, buf, buf_len,
+					event_data_source, CRITICAL_DATA,
+					measure_buf_hash);
+
+	if (queued)
+		return;
+
 	process_buffer_measurement(NULL, buf, buf_len, event_name,
 				   CRITICAL_DATA, 0, event_data_source,
 				   measure_buf_hash);
-- 
2.28.0