RealtimeKit is a D-Bus system service that changes the scheduling policy of user processes/threads to SCHED_RR on request. It is intended to be used as a secure mechanism to allow real-time scheduling to be used by normal user processes. It was found that RealtimeKit communicated with PolicyKit for authorization using a D-Bus API that is vulnerable to a race condition. This could have led to intended PolicyKit authorizations being bypassed. This update modifies RealtimeKit to communicate with PolicyKit via a different API that is not vulnerable to the race condition. All rtkit users are advised to upgrade to this updated package, which contains a backported patch to correct this issue.