# CVE-2026-89453: iommu/amd: Put PCI device after handling PPR faults

> A reference count leak in the AMD IOMMU driver allows attackers to exhaust kernel memory, causing a denial of service.

- **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-2026-89453, DEBIAN-CVE-2026-89453, GHSA-j994-7rwj-c4pp, UBUNTU-CVE-2026-89453

## What is CVE-2026-89453?

CVE-2026-89453 is a denial of service 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:

iommu/amd: Put PCI device after handling PPR faults

iommu_call_iopf_notifier() looks up the requester with
pci_get_domain_bus_and_slot(), which returns a PCI device with its
reference count incremented.

Neither the successful iommu_report_device_fault() path nor the abort
path drops that reference, so every handled PPR request leaks a PCI
device reference.

This is the same ownership rule that was fixed for the old iommu_v2
ppr_notifier() path by commit 6cf0981c2233 ("iommu/amd: Fix pci device
refcount leak in ppr_notifier()"), but iommu_call_iopf_notifier() was
added later as a separate PPR/IOPF notifier path.

Drop the PCI device reference after handling the PPR entry.

## Which versions are affected by CVE-2026-89453?


## How do I fix CVE-2026-89453?

Apply the vendor's patch.

## Is CVE-2026-89453 being exploited?

There is no known exploitation of CVE-2026-89453 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89453 and fix it if it is affected.

What it is: CVE-2026-89453 is a denial of service 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-2026-89453 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-2026-89453/ (Markdown: https://insights.sbomify.com/CVE-2026-89453/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89453
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89453
- OSV: https://osv.dev/vulnerability/CVE-2026-89453

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89453/
Summaries are generated and may contain mistakes; the official description above is the record.