CVE-2025-40076 PCI: rcar-host: Pass proper IRQ domain to generic_handle_domain_irq()
A null pointer dereference in the Linux kernel PCI rcar-host driver causes a system crash when handling MSI interrupts.
- 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-2025-40076?
CVE-2025-40076 is a vulnerability in Linux, published on 28 Oct 2025. 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:
PCI: rcar-host: Pass proper IRQ domain to generic_handle_domain_irq()
Starting with commit dd26c1a23fd5 ("PCI: rcar-host: Switch to msi_create_parent_irq_domain()"), the MSI parent IRQ domain is NULL because the object of type struct irq_domain_info passed to:
msi_create_parent_irq_domain() -> irq_domain_instantiate()() -> __irq_domain_instantiate()
has no reference to the parent IRQ domain. Using msi->domain->parent as an argument for generic_handle_domain_irq() leads to below error:
"Unable to handle kernel NULL pointer dereference at virtual address"
This error was identified while switching the upcoming RZ/G3S PCIe host controller driver to msi_create_parent_irq_domain() (which was using a similar pattern to handle MSIs (see link section)), but it was not tested on hardware using the pcie-rcar-host controller driver due to lack of hardware.
[mani: reworded subject and description]
Which versions are affected by CVE-2025-40076?
How do I fix CVE-2025-40076?
Apply the vendor's patch.
Is CVE-2025-40076 being exploited?
There is no known exploitation of CVE-2025-40076 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40076, GHSA-6gg9-hc2m-2hw4, UBUNTU-CVE-2025-40076.