A flaw was found in the way Libvirtd daemon issued the 'suspend' command to a QEMU guest-agent running inside a guest. It holds a monitor job while issuing the 'suspend' command to a guest-agent. A malicious guest-agent may use this flaw to block the Libvirt daemon indefinitely resulting in a DoS scenario.
Created libvirt tracking bugs for this issue:
Affects: fedora-all [bug 1809741]
Name: Eric Blake (Red Hat Inc.)
This issue affects the version of the libvirt package as shipped with Red Hat Enterprise Linux 7, 8 and Red Hat Enterprise Linux Advanced Virtualization 8. Future libvirt updates for Red Hat Enterprise Linux 7, 8 and Red Hat Enterprise Linux Advanced Virtualization 8 may address this issue.
Red Hat Enterprise Linux version 5 and 6 are in Maintenance Support 2 Phase of the life cycle. This issue has been rated as having Moderate security impact and is not currently planned to be addressed in future updates of the Red Hat Enterprise Linux version 5 and 6. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.