---
id: "CVE-2026-98564"
kind: "vulnerability"
aliases: ["CVE-2026-98564"]
title: "Linux kernel: MT7530 DSA switch driver can crash on removal"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["embedded", "infrastructure", "linux-kernel", "mediatek-switch", "routers"]
not_affected_if: ["driver-not-loaded", "no-mt7530-hardware"]
published_at: "2026-10-18T16:17:08+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:23:20+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98564", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel: MT7530 DSA switch driver can crash on removal

In the Linux kernel's mt7530 DSA switch driver, interrupt mappings for attached PHYs are released too early during device removal, while the switch's interrupt thread can still dispatch on them. The sources describe a kernel fault (NULL descriptor locked) rather than a confirmed remote code execution path.

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

## How to check

- unknown

## Fix

- Update to a Linux kernel release that includes the upstream commit 'net: dsa: mt7530: leave the MDIO IRQ mappings to regmap-irq'
- unknown

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98564

## From the sources

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

net: dsa: mt7530: leave the MDIO IRQ mappings to regmap-irq

mt7530_remove_common() disposes the per-PHY interrupt mappings from
.remove, but the regmap-irq chip that owns the domain is devm-registered,
so its parent interrupt is only freed once .remove has returned. The
switch's own regmap-irq thread can therefore still dispatch on a mapping
that is already gone: irq_find_mapping() returns 0, irq_to_desc() returns
NULL and handle_nested_irq() locks desc->lock without checking it. The
attached PHYs have not given those interrupts back yet either, which the
kernel warns about a moment before the fault.

regmap_del_irq_chip() disposes the same mappings itself, after freeing the
parent interrupt and before removing the domain, so there is nothing left
for the driver to do here. Until it runs the descriptors stay alive, and a
late dispatch on one of them is harmless: dsa_unregister_switch() has freed
the PHY handlers by then, so handle_nested_irq() finds no action and
returns.

---

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