# CVE-2017-18249: Race condition in n/a

> Local attackers can cause a denial of service via a race condition in the Linux kernel's F2FS node management.

- **Severity:** High 7.0 (`CVSS:3.0/AV:L/AC:H/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:** 26 Mar 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2017-18249, GHSA-3g3f-97cc-fc4h, UBUNTU-CVE-2017-18249

## What is CVE-2017-18249?

CVE-2017-18249 is a high-severity vulnerability in Debian Debian Linux, published on 26 Mar 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The add_free_nid function in fs/f2fs/node.c in the Linux kernel before 4.12 does not properly track an allocated nid, which allows local users to cause a denial of service (race condition) or possibly have unspecified other impact via concurrent threads.

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

## Which versions are affected by CVE-2017-18249?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2017-18249?

Upgrade to a fixed version.

## Is CVE-2017-18249 being exploited?

There is no known exploitation of CVE-2017-18249 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-18249 and fix it if it is affected.

What it is: CVE-2017-18249 is a high-severity vulnerability in Debian Debian Linux, published on 26 Mar 2018. 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-2017-18249 in the wild and no public exploit code.

Affected product: Debian Debian 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-2017-18249/ (Markdown: https://insights.sbomify.com/CVE-2017-18249/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-18249
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-18249
- OSV: https://osv.dev/vulnerability/CVE-2017-18249

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-18249/
Summaries are generated and may contain mistakes; the official description above is the record.