Autodiscover memleak (#41748)

* Create a clone to release source struct from mem

* Cleanup meta on stop events

* Add changelog entry

---------

Co-authored-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>

CHANGELOG.next.asciidoc

@@ -127,6 +127,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Fix a bug where log files are rotated on startup when interval is configured and rotateonstartup is disabled {issue}41894[41894] {pull}41895[41895]
 - Fix setting unique registry for non beat receivers {issue}42288[42288] {pull}42292[42292]
 - The Kafka output now drops events when there is an authorisation error {issue}42343[42343] {pull}42401[42401]
+- Fix autodiscovery memory leak related to metadata of start events {pull}41748[41748]
 
 *Auditbeat*
 

libbeat/autodiscover/autodiscover.go

@@ -287,6 +287,11 @@ func (a *Autodiscover) handleStop(event bus.Event) bool {
 		updated = true
 	}
 
+	// Cleanup meta references for this eventID
+	for configHash := range a.configs[eventID] {
+		a.meta.Remove(configHash)
+	}
+
 	delete(a.configs, eventID)
 
 	return updated
@@ -304,7 +309,7 @@ func (a *Autodiscover) getMeta(event bus.Event) mapstr.M {
 		a.logger.Errorf("Got a wrong meta field for event %v", event)
 		return nil
 	}
-	return meta
+	return meta.Clone()
 }
 
 // getID returns the event "id" field string if present