CVE-2026-89455: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved:

PCI: plda: Fix use-after-free of event IRQs during teardown

plda_pcie_irq_domain_deinit() removes pcie->event_domain via irq_domain_remove(), but the per-event IRQs mapped from that domain are requested with devm_request_irq() in plda_init_interrupts(). The actual free_irq() for a devm-managed IRQ is deferred by devres until after the calling probe()/remove() function returns.

This means irq_domain_remove() can free the domain's internal data before the deferred free_irq() for IRQs still mapped into it has run. When devres later processes that deferred cleanup, it can end up dereferencing the already-freed domain.

Free each event IRQ explicitly with devm_free_irq() before removing the domain. This triggers the free immediately and removes the IRQ from the devres tracking list, so devres will not attempt to free it a second time later.

Also dispose of the event, INTx, and MSI IRQ mappings with irq_dispose_mapping() before their owning domains are removed.

Finally, guard the calls to irq_set_chained_handler_and_data() for pcie->irq, pcie->msi_irq, and pcie->intx_irq so they only run when those fields hold a valid (>0) IRQ number.

This is a pre-existing issue, flagged by automated review during work on an earlier, unrelated patch to this driver.

Build-tested and boot-tested on StarFive VisionFive v1.2A board