---
title: "CVE-2009-4307\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2009-4307?format=md
keywords: index, follow
---

# CVE-2009-4307

Publication date 13 December 2009

Last updated 24 July 2024

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

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## Description

The ext4\_fill\_flex\_info function in fs/ext4/super.c in the Linux kernel
before 2.6.32-git6 allows user-assisted remote attackers to cause a denial
of service (divide-by-zero error and panic) via a malformed ext4 filesystem
containing a super block with a large FLEX\_BG group size (aka
s\_log\_groups\_per\_flex value).

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| linux | 9.10 karmic | Not affected |
| 9.04 jaunty | Not affected |
| 8.10 intrepid | Not affected |
| 8.04 LTS hardy | Not affected |
| 6.06 LTS dapper | Not in release |
| linux-source-2.6.15 | 9.10 karmic | Not in release |
| 9.04 jaunty | Not in release |
| 8.10 intrepid | Not in release |
| 8.04 LTS hardy | Not in release |
| 6.06 LTS dapper | Not affected |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-4307)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2009-4307)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2009-4307)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2009-4307)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2009-4307>