# 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.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89455, DEBIAN-CVE-2026-89455, GHSA-8qqp-mrfh-pvx7, UBUNTU-CVE-2026-89455

## 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.

## Is CVE-2026-89455 being exploited?

There is no known exploitation of CVE-2026-89455 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89455 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-89455 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-89455/ (Markdown: https://insights.sbomify.com/CVE-2026-89455/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89455
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89455
- OSV: https://osv.dev/vulnerability/CVE-2026-89455

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89455/
Summaries are generated and may contain mistakes; the official description above is the record.