CVE-2026-98564 net: dsa: mt7530: leave the MDIO IRQ mappings to regmap-irq
A race condition in the mt7530 DSA driver causes a null pointer dereference during device removal, leading to a kernel crash.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98564?
CVE-2026-98564 is a vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-98564?
How do I fix CVE-2026-98564?
Apply the vendor's patch.
Is CVE-2026-98564 being exploited?
There is no known exploitation of CVE-2026-98564 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98564, DEBIAN-CVE-2026-98564, GHSA-843v-cg64-5wvw, UBUNTU-CVE-2026-98564.