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CRE-2024-0018

Neutron Open Virtual Network (OVN) high CPU usageMedium
Impact: 4/10
Mitigation: 5/10

CRE-2024-0018View on GitHub

Description

OVN daemons (e.g., ovn-controller) are stuck in a tight poll loop, driving CPU to 100 %. Logs show “Dropped … due to excessive rate” or

“Unreasonably long … poll interval,” slowing port-binding and network traffic.


Cause

  • Probe interval too low leads to constant keep-alives
  • Burst of logical-flow updates (security-groups, LB changes)
  • Poll-loop bug in OVN ≤ 20.2.0
  • CPU contention with GPU workloads; no offload/D PDK

Mitigation

Increase the OVN remote probe interval to 30 seconds:

ovs-vsctl set open . external_ids:ovn-remote-probe-interval=30000

References