# CVE-2023-2612: shiftfs lock unbalance in Ubuntu-specific kernels

> A local attacker can exploit a race condition in the shiftfs file system to cause a kernel deadlock, resulting in denial of service.

- **Severity:** Medium 4.4 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 May 2023
- **Updated:** 13 Feb 2025
- **Also known as:** GHSA-r34w-xrj9-cpvr, UBUNTU-CVE-2023-2612

## What is CVE-2023-2612?

CVE-2023-2612 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 30 May 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Jean-Baptiste Cayrou discovered that the shiftfs file system in the Ubuntu Linux kernel contained a race condition when handling inode locking in some situations. A local attacker could use this to cause a denial of service (kernel deadlock).

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2023-2612?

It affects 1 product.


Products: Canonical Ubuntu Linux.

## How do I fix CVE-2023-2612?

Apply the vendor's patch.

## Is CVE-2023-2612 being exploited?

There is no known exploitation of CVE-2023-2612 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-2612 and fix it if it is affected.

What it is: CVE-2023-2612 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 30 May 2023. 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-2023-2612 in the wild and no public exploit code.

Affected product: Canonical Ubuntu 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-2023-2612/ (Markdown: https://insights.sbomify.com/CVE-2023-2612/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-2612
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-2612
- OSV: https://osv.dev/vulnerability/CVE-2023-2612

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-2612/
Summaries are generated and may contain mistakes; the official description above is the record.