# CVE-2026-93200: i3c: master: Fix use-after-free of master->this

> A use-after-free in the Linux kernel I3C master driver allows local attackers to execute arbitrary code or escalate privileges via sysfs access.

- **Severity:** Not scored
- **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:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-102198, BELL-CVE-2026-93200, DEBIAN-CVE-2026-93200, GHSA-353r-jvg2-63v3, UBUNTU-CVE-2026-93200

## What is CVE-2026-93200?

CVE-2026-93200 is an use after free vulnerability in Linux, published on 17 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 use-after-free of master->this

sysfs attribute callbacks for the master controller device dereference
master->this.  However, master->this is freed in
i3c_master_detach_free_devs() before the master device itself is
released.

As a result, sysfs accesses can dereference a freed master->this
pointer, leading to a use-after-free.

Keep master->this alive until i3c_masterdev_release(), which is called
after the master device and its sysfs state are being torn down. Do not
free master->this as part of the normal device detach path.

On the error path in i3c_master_set_info(), reset master->this and
bus.cur_master to NULL before freeing the allocated device.

## Which versions are affected by CVE-2026-93200?


## How do I fix CVE-2026-93200?

Apply the vendor's patch.

## Is CVE-2026-93200 being exploited?

There is no known exploitation of CVE-2026-93200 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93200 and fix it if it is affected.

What it is: CVE-2026-93200 is an use after free vulnerability in Linux, published on 17 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-2026-93200 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-2026-93200/ (Markdown: https://insights.sbomify.com/CVE-2026-93200/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93200
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93200
- OSV: https://osv.dev/vulnerability/CVE-2026-93200

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93200/
Summaries are generated and may contain mistakes; the official description above is the record.