# CVE-2026-80952: i3c: master: Fix info leak and UAF in device unregister path

> A use-after-free and information leak in the Linux kernel i3c master driver allows attackers to read kernel stack memory or potentially execute code during device unregistration.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **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:** AZL-100211, BELL-CVE-2026-80952, DEBIAN-CVE-2026-80952, GHSA-m64m-jwhp-5878, UBUNTU-CVE-2026-80952

## What is CVE-2026-80952?

CVE-2026-80952 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:

i3c: master: Fix info leak and UAF in device unregister path

i3c_master_unregister_i3c_devs() clears i3cdev->dev->desc before
calling device_unregister().  During device_unregister(),
device_del() emits a KOBJ_REMOVE uevent and unbinds the driver while
the device descriptor is still expected to be valid.  As a result,
i3c_device_uevent() and a racing modalias_show() can observe a NULL
desc and fall back to an uninitialized stack struct i3c_device_info,
leaking kernel stack contents in the generated modalias.  Driver
.remove() callbacks may also encounter an unexpected NULL desc during
unbind.

Keep desc valid until device_unregister() has completed.  Since
device_unregister() drops the device reference and may free the device,
take an extra reference with get_device() before unregistering.  Clear
desc afterwards and release the extra reference with put_device().
This preserves the release-time invariant that desc must be NULL while
avoiding both the information leak and a potential use-after-free from
writing desc after the device has been released.

## Which versions are affected by CVE-2026-80952?


## How do I fix CVE-2026-80952?

Apply the vendor's patch.

## Is CVE-2026-80952 being exploited?

There is no known exploitation of CVE-2026-80952 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80952 and fix it if it is affected.

What it is: CVE-2026-80952 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-2026-80952 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-2026-80952/ (Markdown: https://insights.sbomify.com/CVE-2026-80952/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80952
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80952
- OSV: https://osv.dev/vulnerability/CVE-2026-80952

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80952/
Summaries are generated and may contain mistakes; the official description above is the record.