https://bugs.openldap.org/show_bug.cgi?id=10448
--- Comment #1 from Howard Chu hyc@openldap.org --- This does not appear to be a valid report. The sync_control structure is allocated in the operation's tmpmemctx, therefore it is implicitly disposed of when the operation completes.
The stack trace you provide would only have occurred if the operation was invoked without any tmpmemctx provided, which slapd doesn't do.