---
id: "CVE-2026-98948"
kind: "vulnerability"
aliases: ["CVE-2026-98948"]
title: "Linux kernel: mlxsw template creation leaks port range registers"
severity: "unknown"
cvss: null
epss: 0.00209
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["linux-kernel", "mlxsw", "network-switch", "runtime"]
not_affected_if: ["driver-not-loaded", "no-spectrum-hardware"]
published_at: "2026-10-23T13:17:15+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98948", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-98948", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux kernel: mlxsw template creation leaks port range registers

In the Linux kernel's Mellanox Spectrum switch driver (mlxsw), creating a flower classifier template acquires port range registers that are never released. The leak occurs in the template create and delete path, so repeated use can exhaust those hardware resources.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98948
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-98948

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

mlxsw: spectrum_flower: Fix port range register leak in tmplt_create()

mlxsw_sp_flower_tmplt_create() parses a flow_cls_offload template
into a stack-local struct mlxsw_sp_acl_rule_info purely to compute
rulei.values.elusage. Parsing can acquire port range registers via
mlxsw_sp_flower_parse_ports_range(), but since this rulei never goes
through mlxsw_sp_acl_rulei_destroy(), those registers were never
released, including through chain template deletion.

Factor out of mlxsw_sp_acl_rulei_destroy() the code to actually
release the necessary resources and call from
mlxsw_sp_flower_tmplt_create() to plug the leak.

The issue was found during a review of Wentao Liang's patch referenced
below.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_