# CVE-2023-53820: loop: loop_set_status_from_info() check before assignment

> An integer overflow in the Linux kernel loop driver can cause incorrect offset assignments, leading to potential 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:** 9 Dec 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2023-53820, DEBIAN-CVE-2023-53820, GHSA-3f7g-86g8-7vgv, UBUNTU-CVE-2023-53820

## What is CVE-2023-53820?

CVE-2023-53820 is a vulnerability in Linux, published on 9 Dec 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:

loop: loop_set_status_from_info() check before assignment

In loop_set_status_from_info(), lo->lo_offset and lo->lo_sizelimit should
be checked before reassignment, because if an overflow error occurs, the
original correct value will be changed to the wrong value, and it will not
be changed back.

More, the original patch did not solve the problem, the value was set and
ioctl returned an error, but the subsequent io used the value in the loop
driver, which still caused an alarm:

loop_handle_cmd
 do_req_filebacked
  loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
  lo_rw_aio
   cmd->iocb.ki_pos = pos

## Which versions are affected by CVE-2023-53820?


## How do I fix CVE-2023-53820?

Apply the vendor's patch.

## Is CVE-2023-53820 being exploited?

There is no known exploitation of CVE-2023-53820 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53820 and fix it if it is affected.

What it is: CVE-2023-53820 is a vulnerability in Linux, published on 9 Dec 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-2023-53820 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-2023-53820/ (Markdown: https://insights.sbomify.com/CVE-2023-53820/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53820
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53820
- OSV: https://osv.dev/vulnerability/CVE-2023-53820

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53820/
Summaries are generated and may contain mistakes; the official description above is the record.