CVE-2025-40076PCI: rcar-host: Pass proper IRQ domain to generic_handle_domain_irq()

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]

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/e8e21aaf5d34015901cd271053a67a62b4204526
• https://git.kernel.org/stable/c/d3fee10e40a938331e2aae34348691136db31304