CVE-2026-98564: net: dsa: mt7530: leave the MDIO IRQ mappings to regmap-irq
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mt7530: leave the MDIO IRQ mappings to regmap-irq
mt7530removecommon() 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: irqfindmapping() returns 0, irqtodesc() returns NULL and handlenestedirq() 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.
regmapdelirqchip() 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: dsaunregisterswitch() has freed the PHY handlers by then, so handlenestedirq() finds no action and returns.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
In mt7530_remove_common(), do not dispose the per-PHY MDIO interrupt mappings; leave them to regmap-irq, whose regmap_del_irq_chip() call disposes the mappings after freeing the parent interrupt.