# CVE-2023-53171: vfio/type1: prevent underflow of locked_vm via exec()

> A local attacker can cause a denial of service in the Linux kernel by triggering an integer underflow in VFIO locked_vm accounting via exec().

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/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:** 15 Sep 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53171, DEBIAN-CVE-2023-53171, GHSA-w3pr-pqpr-2f83, UBUNTU-CVE-2023-53171

## What is CVE-2023-53171?

CVE-2023-53171 is a medium-severity vulnerability in Linux kernel, published on 15 Sep 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:

vfio/type1: prevent underflow of locked_vm via exec()

When a vfio container is preserved across exec, the task does not change,
but it gets a new mm with locked_vm=0, and loses the count from existing
dma mappings.  If the user later unmaps a dma mapping, locked_vm underflows
to a large unsigned value, and a subsequent dma map request fails with
ENOMEM in __account_locked_vm.

To avoid underflow, grab and save the mm at the time a dma is mapped.
Use that mm when adjusting locked_vm, rather than re-acquiring the saved
task's mm, which may have changed.  If the saved mm is dead, do nothing.

locked_vm is incremented for existing mappings in a subsequent patch.

## Which versions are affected by CVE-2023-53171?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53171?

Apply the vendor's patch.

## Is CVE-2023-53171 being exploited?

There is no known exploitation of CVE-2023-53171 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-2023-53171 and fix it if it is affected.

What it is: CVE-2023-53171 is a medium-severity vulnerability in Linux kernel, published on 15 Sep 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-2023-53171 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-2023-53171/ (Markdown: https://insights.sbomify.com/CVE-2023-53171/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53171
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53171
- OSV: https://osv.dev/vulnerability/CVE-2023-53171

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53171/
Summaries are generated and may contain mistakes; the official description above is the record.