# CVE-2026-90224: nfc: nci: fix double completion race in nci_data_exchange_complete

> A race condition in the Linux kernel NFC driver allows double completion, leading to use-after-free and potential code execution or denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:A/AC:H/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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102059, BELL-CVE-2026-90224, DEBIAN-CVE-2026-90224, GHSA-xj24-p6ph-p2w7, UBUNTU-CVE-2026-90224

## What is CVE-2026-90224?

CVE-2026-90224 is a high-severity 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:

nfc: nci: fix double completion race in nci_data_exchange_complete

nci_close_device() and nci_rx_work can both call
nci_data_exchange_complete() concurrently.  After commit 4527025d440ce8
("nfc: nci: fix circular locking dependency in nci_close_device") moved
flush_workqueue(ndev->rx_wq) after mutex_unlock(&ndev->req_lock),
rx_work is no longer serialized with the explicit completion call in the
close path.  Both callers read the non-NULL callback pointer and invoke
rawsock_data_exchange_complete(), which calls sock_put() -- but only one
sock_hold() was taken, so the second sock_put() underflows the refcount
and frees the socket while it is still in use.

Replace the bare clear_bit(NCI_DATA_EXCHANGE) with
test_and_clear_bit() so that only the first caller proceeds to invoke
the callback.

## Which versions are affected by CVE-2026-90224?


## How do I fix CVE-2026-90224?

Apply the vendor's patch.

## Is CVE-2026-90224 being exploited?

There is no known exploitation of CVE-2026-90224 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90224 and fix it if it is affected.

What it is: CVE-2026-90224 is a high-severity 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-2026-90224 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-2026-90224/ (Markdown: https://insights.sbomify.com/CVE-2026-90224/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90224
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90224
- OSV: https://osv.dev/vulnerability/CVE-2026-90224

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90224/
Summaries are generated and may contain mistakes; the official description above is the record.