# CVE-2024-42131: mm: avoid overflows in dirty throttling logic

> A root user can trigger integer overflows in Linux kernel dirty throttling logic by setting excessive memory limits, potentially causing system instability or crashes.

- **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 Jul 2024
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2024-42131, DEBIAN-CVE-2024-42131, GHSA-vc72-g5gr-jp4w, UBUNTU-CVE-2024-42131

## What is CVE-2024-42131?

CVE-2024-42131 is a medium-severity vulnerability in Linux kernel, published on 30 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

mm: avoid overflows in dirty throttling logic

The dirty throttling logic is interspersed with assumptions that dirty
limits in PAGE_SIZE units fit into 32-bit (so that various multiplications
fit into 64-bits).  If limits end up being larger, we will hit overflows,
possible divisions by 0 etc.  Fix these problems by never allowing so
large dirty limits as they have dubious practical value anyway.  For
dirty_bytes / dirty_background_bytes interfaces we can just refuse to set
so large limits.  For dirty_ratio / dirty_background_ratio it isn't so
simple as the dirty limit is computed from the amount of available memory
which can change due to memory hotplug etc.  So when converting dirty
limits from ratios to numbers of pages, we just don't allow the result to
exceed UINT_MAX.

This is root-only triggerable problem which occurs when the operator
sets dirty limits to >16 TB.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2024-42131?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-42131?

Apply the vendor's patch.

## Is CVE-2024-42131 being exploited?

There is no known exploitation of CVE-2024-42131 in the wild and no public exploit code.

## 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-2024-42131 and fix it if it is affected.

What it is: CVE-2024-42131 is a medium-severity vulnerability in Linux kernel, published on 30 Jul 2024. 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-2024-42131 in the wild and no public exploit code.

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-2024-42131/ (Markdown: https://insights.sbomify.com/CVE-2024-42131/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-42131
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-42131
- OSV: https://osv.dev/vulnerability/CVE-2024-42131

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-42131/
Summaries are generated and may contain mistakes; the official description above is the record.