When generating an ICMP Destination Unreachable or Packet Too Big response, the handler copies a portion of the original packet into the ICMP error body using the IP header's self-declared total length (ip_tot_len for IPv4, ip6_plen for IPv6) without validating it against the actual packet buffer size. A VM can send a short packet with an inflated IP length field that triggers an ICMP error (e.g., by hitting a reject ACL), causing ovn-controller to read heap memory beyond the valid packet data and include it in the ICMP response sent back to the VM.
https://access.redhat.com/errata/RHSA-2026:22111
https://access.redhat.com/errata/RHSA-2026:22110
https://access.redhat.com/errata/RHSA-2026:11702
https://access.redhat.com/errata/RHSA-2026:11701
https://access.redhat.com/errata/RHSA-2026:11700
https://access.redhat.com/errata/RHSA-2026:11698
https://access.redhat.com/errata/RHSA-2026:11696