CVE-2025-68266

Summary

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).

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < d0c5ec1f57d8fbb953f166a27d9d32473dc8f3e4affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < aeccd6743ee4fdd1ab8cfcbb5b9a20b613418f6daffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8f73336b75bd3457b6f9410f2a0601a238f32238affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a9f626396bfe66f49b743601e862767928237cc0affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 77899444d46162aeb65f229590c26ba266864223affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a8cb796e7e2cb7971311ba236922f5e7e1be77e6affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 34ab4c75588c07cca12884f2bf6b0347c7a13872affected
LinuxLinux2.6.12affected
LinuxLinux0 < 2.6.12unaffected
LinuxLinux5.10.248 <= 5.10.*unaffected
LinuxLinux5.15.198 <= 5.15.*unaffected
LinuxLinux6.1.160 <= 6.1.*unaffected
LinuxLinux6.6.120 <= 6.6.*unaffected
LinuxLinux6.12.62 <= 6.12.*unaffected
LinuxLinux6.17.12 <= 6.17.*unaffected
LinuxLinux6.18 <= *unaffected

Weaknesses

References