# CVE-2026-89452: iommu/msm: Unwind probe state on registration failure

> A use-after-free vulnerability in the Linux kernel MSM IOMMU driver allows attackers to cause a denial of service or potentially execute code via dangling list entries.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 21 Oct 2026
- **Also known as:** AZL-100817, BELL-CVE-2026-89452, DEBIAN-CVE-2026-89452, GHSA-g6rr-fv4f-cc2j, UBUNTU-CVE-2026-89452

## What is CVE-2026-89452?

CVE-2026-89452 is a high-severity 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:

iommu/msm: Unwind probe state on registration failure

msm_iommu_probe() adds its devm-managed IOMMU object to
qcom_iommu_devices before adding the IOMMU sysfs device and registering
it with the IOMMU core.

If iommu_device_sysfs_add() fails, probe returns with the object still on
qcom_iommu_devices. The driver core then releases the devm allocation,
leaving a dangling list entry that later list walks may dereference.

If iommu_device_register() fails, the same dangling list entry remains
and the sysfs device is left registered as well.

Unwind the sysfs device and global list entry in reverse setup order on
the corresponding failure paths.

## Which versions are affected by CVE-2026-89452?


## How do I fix CVE-2026-89452?

Apply the vendor's patch.

## Is CVE-2026-89452 being exploited?

There is no known exploitation of CVE-2026-89452 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89452 and fix it if it is affected.

What it is: CVE-2026-89452 is a high-severity 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-2026-89452 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-2026-89452/ (Markdown: https://insights.sbomify.com/CVE-2026-89452/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89452
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89452
- OSV: https://osv.dev/vulnerability/CVE-2026-89452

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89452/
Summaries are generated and may contain mistakes; the official description above is the record.