# CVE-2009-0746: Denial of service in n/a

> Local attackers can cause a denial of service by mounting a crafted ext4 filesystem due to missing validation in the Linux kernel.

- **Severity:** Medium 4.9 (`AV:L/AC:L/Au:N/C:N/I:N/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 Feb 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-gprc-5h5v-mh5j

## What is CVE-2009-0746?

CVE-2009-0746 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Feb 2009. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

The make_indexed_dir function in fs/ext4/namei.c in the Linux kernel 2.6.27 before 2.6.27.19 and 2.6.28 before 2.6.28.7 does not validate a certain rec_len field, which allows local users to cause a denial of service (OOPS) by attempting to mount a crafted ext4 filesystem.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2009-0746?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2009-0746?

Apply the vendor's patch.

## Is CVE-2009-0746 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-0746 exists.

Public exploit code:

- Linux Kernel 2.6.x - 'make_indexed_dir()' Local Denial of Service (exploitdb)

## 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-2009-0746 and fix it if it is affected.

What it is: CVE-2009-0746 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Feb 2009. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-0746 exists.

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-2009-0746/ (Markdown: https://insights.sbomify.com/CVE-2009-0746/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-0746
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-0746
- OSV: https://osv.dev/vulnerability/CVE-2009-0746

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-0746/
Summaries are generated and may contain mistakes; the official description above is the record.