# CVE-2026-93214: usb: gadget: f_tcm: fix deadlock in usbg_make_tpg()

> A local attacker with USB gadget configuration access can trigger a kernel deadlock, causing a denial of service.

- **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:** 24 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93214, DEBIAN-CVE-2026-93214, GHSA-wwm2-chq9-c6mx, UBUNTU-CVE-2026-93214

## What is CVE-2026-93214?

CVE-2026-93214 is a denial of service vulnerability in Linux, published on 24 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:

usb: gadget: f_tcm: fix deadlock in usbg_make_tpg()

usbg_make_tpg() held dep_lock while calling
configfs_depend_item_unlocked(), which acquires the configfs root
inode lock when operating across subsystems. This creates a circular
lock dependency with configfs_rmdir():

  dep_lock -> configfs root inode lock -> su_mutex -> dep_lock

In usbg_make_tpg(), dep_lock only serialized the read of opts->ready,
which is a monotonic flag that transitions from false to true exactly
once (in tcm_set_name()) and never reverts. Remove dep_lock from
usbg_make_tpg() entirely and use READ_ONCE/WRITE_ONCE to access
opts->ready locklessly instead.

## Which versions are affected by CVE-2026-93214?


## How do I fix CVE-2026-93214?

Apply the vendor's patch.

## Is CVE-2026-93214 being exploited?

There is no known exploitation of CVE-2026-93214 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93214 and fix it if it is affected.

What it is: CVE-2026-93214 is a denial of service vulnerability in Linux, published on 24 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-2026-93214 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-2026-93214/ (Markdown: https://insights.sbomify.com/CVE-2026-93214/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93214
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93214
- OSV: https://osv.dev/vulnerability/CVE-2026-93214

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93214/
Summaries are generated and may contain mistakes; the official description above is the record.