CVE-2026-89455 PCI: plda: Fix use-after-free of event IRQs during teardown
A use-after-free vulnerability in the Linux kernel PCI plda driver allows local attackers to cause a denial of service or potentially execute code during device teardown.
- 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-2026-89455?
CVE-2026-89455 is an use after free vulnerability in Linux, published on 11 Sep 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:
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
Which versions are affected by CVE-2026-89455?
How do I fix CVE-2026-89455?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-89455 being exploited?
There is no known exploitation of CVE-2026-89455 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89455, DEBIAN-CVE-2026-89455, GHSA-8qqp-mrfh-pvx7, UBUNTU-CVE-2026-89455.