CVE-2026-97966
Received Received - Intake

Memory Leak in Linux Kernel HTB Scheduler

Publication date: 2026-09-25

Last updated on: 2026-09-25

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: octeontx2-pf: reset HTB scheduler topology before freeing queues HTB offload programs NIX_AF_TLxX_TOPOLOGY on QoS-allocated scheduler queues via otx2_qos_txschq_set_parent_topology(), but teardown freed those queues without clearing TOPOLOGY. The AF only restores PARENT and SCHEDULE on free, so PRIO_ANCHOR/RR_PRIO settings can survive in the shared scheduler pool and affect later allocations. Add otx2_qos_reset_schq_topology() and otx2_qos_free_hw_schq() to zero TL4 through TL2 TOPOLOGY before each schq is returned to the AF during hierarchy teardown and cfg rollback. Skip the aggregation level (TL1): it is a per-tx-link queue shared by the PF, default Tx hierarchy and VFs, and is not freed back to the AF by nix_txschq_free_one().

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Meta Information

Published
2026-09-25
Last Modified
2026-09-25
Generated
2026-09-25
AI Q&A
2026-09-25
EPSS Evaluated
N/A
NVD
CVE-2026-97966
EUVD
EUVD-2026-86820

Affected Vendors & Products

Currently, no data is known.

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves improper cleanup of HTB scheduler queues in the octeontx2-pf driver. During teardown, queues are freed without clearing topology settings, leaving PRIO_ANCHOR and RR_PRIO values in the shared scheduler pool. This can affect later allocations and cause unintended behavior in network traffic management.

Detection Guidance

This vulnerability affects the Linux kernel's octeontx2-pf driver and HTB scheduler. Detection requires checking kernel logs for HTB scheduler errors or examining the octeontx2-pf driver behavior during queue teardown. No specific commands are provided in the context.

Impact Analysis

If exploited, this flaw could lead to incorrect network traffic prioritization or scheduling, potentially causing performance degradation or denial of service. Systems using HTB offload in QoS configurations may experience unexpected behavior during queue teardown or reconfiguration.

Mitigation Strategies

Update the Linux kernel to a patched version that includes the fix for CVE-2026-97966. The patch adds otx2_qos_reset_schq_topology() to clear scheduler topology during queue teardown.

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