CVE-2026-98564
Received Received - Intake

Use-After-Free in Linux Kernel MT7530 Switch Driver

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
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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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-18
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98564
EUVD
EUVD-2026-103609

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
Linux Linux 254f6b272e3b67bf31c42ee9da62a449d74d1478
Linux Linux 254f6b272e3b67bf31c42ee9da62a449d74d1478
Linux Linux 254f6b272e3b67bf31c42ee9da62a449d74d1478
Linux Linux 6.15

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Exploitability

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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 handling of MDIO IRQ mappings in the mt7530 network switch driver. The issue occurs when mt7530_remove_common() removes interrupt mappings while the regmap-irq chip's parent interrupt is still active, leading to a race condition where handle_nested_irq() may access freed interrupt descriptors.

Detection Guidance

This vulnerability is specific to the Linux kernel's mt7530 network switch driver and involves interrupt handling issues. Detection requires checking kernel logs for warnings about interrupt mappings or nested IRQ faults. Use commands like dmesg | grep -i irq or journalctl -k | grep -i irq to inspect for related errors.

Impact Analysis

This vulnerability could cause kernel crashes or instability due to accessing freed memory during interrupt handling. Systems using affected Linux kernels with mt7530 network switches may experience unexpected reboots or denial of service conditions.

Mitigation Strategies

Update the Linux kernel to a patched version where this issue is resolved. Monitor kernel logs for any interrupt-related warnings after applying updates. If affected, avoid using the mt7530 switch driver until the fix is applied.

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