CVE-2026-74696 (GCVE-0-2026-74696)
Vulnerability from cvelistv5
Published
2026-08-22 15:32
Modified
2026-10-16 19:16
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: tcp: fix TFO max_qlen accounting across reuseport migration A listener's TCP_FASTOPEN max_qlen stops being accurate and lets through far more pending Fast Open requests than it was configured for. This only shows up with SO_REUSEPORT listener migration, where closing a listener hands its still-pending TFO children over to a surviving one. fastopenq.qlen is charged in tcp_fastopen_create_child() when the child is created and uncharged in reqsk_fastopen_remove() when the handshake completes. The uncharge follows rsk_listener of the request the child points at, and inet_reqsk_clone() has repointed the child at a new request owned by the new listener, so the ++ and the -- land on two different sockets. The new listener's qlen drifts negative and its limit no longer binds. Charge the new listener during migration, like reqsk_queue_migrated() already does for queue->young and queue->qlen.
References
Impacted products
Vendor Product Version
Linux Linux Version: 54b92e84193749c9968aff2dd46e3b0f42643e18
Version: 54b92e84193749c9968aff2dd46e3b0f42643e18
Version: 54b92e84193749c9968aff2dd46e3b0f42643e18
Version: 54b92e84193749c9968aff2dd46e3b0f42643e18
Version: 54b92e84193749c9968aff2dd46e3b0f42643e18
Version: 54b92e84193749c9968aff2dd46e3b0f42643e18
Version: 54b92e84193749c9968aff2dd46e3b0f42643e18
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