# CVE-2026-23463: soc: fsl: qbman: fix race condition in qman_destroy_fq

> A race condition in the Linux kernel's FSL QBMAN driver can trigger a kernel warning and potential denial of service during frame queue destruction.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/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:** 3 Apr 2026
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2026-23463, DEBIAN-CVE-2026-23463, GHSA-cxrg-39g8-v6cj, ROOT-OS-DEBIAN-11-CVE-2026-23463, ROOT-OS-DEBIAN-12-CVE-2026-23463, ROOT-OS-DEBIAN-13-CVE-2026-23463, ROOT-OS-UBUNTU-2204-CVE-2026-23463, ROOT-OS-UBUNTU-2404-CVE-2026-23463, UBUNTU-CVE-2026-23463

## What is CVE-2026-23463?

CVE-2026-23463 is a medium-severity vulnerability in Linux kernel, published on 3 Apr 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:

soc: fsl: qbman: fix race condition in qman_destroy_fq

When QMAN_FQ_FLAG_DYNAMIC_FQID is set, there's a race condition between
fq_table[fq->idx] state and freeing/allocating from the pool and
WARN_ON(fq_table[fq->idx]) in qman_create_fq() gets triggered.

Indeed, we can have:
         Thread A                             Thread B
    qman_destroy_fq()                    qman_create_fq()
      qman_release_fqid()
        qman_shutdown_fq()
        gen_pool_free()
           -- At this point, the fqid is available again --
                                           qman_alloc_fqid()
           -- so, we can get the just-freed fqid in thread B --
                                           fq->fqid = fqid;
                                           fq->idx = fqid * 2;
                                           WARN_ON(fq_table[fq->idx]);
                                           fq_table[fq->idx] = fq;
     fq_table[fq->idx] = NULL;

And adding some logs between qman_release_fqid() and
fq_table[fq->idx] = NULL makes the WARN_ON() trigger a lot more.

To prevent that, ensure that fq_table[fq->idx] is set to NULL before
gen_pool_free() is called by using smp_wmb().

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-23463?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23463?

Apply the vendor's patch.

## Is CVE-2026-23463 being exploited?

There is no known exploitation of CVE-2026-23463 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23463 and fix it if it is affected.

What it is: CVE-2026-23463 is a medium-severity vulnerability in Linux kernel, published on 3 Apr 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-2026-23463 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-23463/ (Markdown: https://insights.sbomify.com/CVE-2026-23463/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23463
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23463
- OSV: https://osv.dev/vulnerability/CVE-2026-23463

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23463/
Summaries are generated and may contain mistakes; the official description above is the record.