# CVE-2023-53698: xsk: fix refcount underflow in error path

> A refcount underflow in the Linux kernel XSK subsystem can cause a denial of service when memory allocation fails during socket setup.

- **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:** 22 Oct 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2023-53698, DEBIAN-CVE-2023-53698, GHSA-f7vc-g3xh-9xx2, UBUNTU-CVE-2023-53698

## What is CVE-2023-53698?

CVE-2023-53698 is a high-severity vulnerability in Linux, published on 22 Oct 2025. 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:

xsk: fix refcount underflow in error path

Fix a refcount underflow problem reported by syzbot that can happen
when a system is running out of memory. If xp_alloc_tx_descs() fails,
and it can only fail due to not having enough memory, then the error
path is triggered. In this error path, the refcount of the pool is
decremented as it has incremented before. However, the reference to
the pool in the socket was not nulled. This means that when the socket
is closed later, the socket teardown logic will think that there is a
pool attached to the socket and try to decrease the refcount again,
leading to a refcount underflow.

I chose this fix as it involved adding just a single line. Another
option would have been to move xp_get_pool() and the assignment of
xs->pool to after the if-statement and using xs_umem->pool instead of
xs->pool in the whole if-statement resulting in somewhat simpler code,
but this would have led to much more churn in the code base perhaps
making it harder to backport.

## Which versions are affected by CVE-2023-53698?


## How do I fix CVE-2023-53698?

Apply the vendor's patch.

## Is CVE-2023-53698 being exploited?

There is no known exploitation of CVE-2023-53698 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53698 and fix it if it is affected.

What it is: CVE-2023-53698 is a high-severity vulnerability in Linux, published on 22 Oct 2025. 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-2023-53698 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-2023-53698/ (Markdown: https://insights.sbomify.com/CVE-2023-53698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53698
- OSV: https://osv.dev/vulnerability/CVE-2023-53698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53698/
Summaries are generated and may contain mistakes; the official description above is the record.