In the Linux kernel, the following vulnerability has been resolved: bfs: Reconstruct file type...
🔗 CVE IDs covered (1)
📋 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).
🔗 References (10)
- https://nvd.nist.gov/vuln/detail/CVE-2025-68266
- https://git.kernel.org/stable/c/34ab4c75588c07cca12884f2bf6b0347c7a13872
- https://git.kernel.org/stable/c/77899444d46162aeb65f229590c26ba266864223
- https://git.kernel.org/stable/c/a8cb796e7e2cb7971311ba236922f5e7e1be77e6
- https://git.kernel.org/stable/c/8f73336b75bd3457b6f9410f2a0601a238f32238
- https://git.kernel.org/stable/c/a9f626396bfe66f49b743601e862767928237cc0
- https://git.kernel.org/stable/c/aeccd6743ee4fdd1ab8cfcbb5b9a20b613418f6d
- https://git.kernel.org/stable/c/d0c5ec1f57d8fbb953f166a27d9d32473dc8f3e4
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://github.com/advisories/GHSA-cf7w-xh8m-r378