CVE-2025-68794 (GCVE-0-2025-68794)

Vulnerability from cvelistv5 – Published: 2026-01-13 15:29 – Updated: 2026-01-13 15:29
VLAI?
Title
iomap: adjust read range correctly for non-block-aligned positions
Summary
In the Linux kernel, the following vulnerability has been resolved: iomap: adjust read range correctly for non-block-aligned positions iomap_adjust_read_range() assumes that the position and length passed in are block-aligned. This is not always the case however, as shown in the syzbot generated case for erofs. This causes too many bytes to be skipped for uptodate blocks, which results in returning the incorrect position and length to read in. If all the blocks are uptodate, this underflows length and returns a position beyond the folio. Fix the calculation to also take into account the block offset when calculating how many bytes can be skipped for uptodate blocks.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 82b60ffbb532d919959702768dca04c3c0500ae5 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 12053695c8ef5410e8cc6c9ed4c0db9cd9c82b3e (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 142194fb21afe964d2d194cab1fc357cbf87e899 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 7aa6bc3e8766990824f66ca76c19596ce10daf3e (git)
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    Linux Linux Unaffected: 6.6.120 , ≤ 6.6.* (semver)
Unaffected: 6.12.64 , ≤ 6.12.* (semver)
Unaffected: 6.18.3 , ≤ 6.18.* (semver)
Unaffected: 6.19-rc1 , ≤ * (original_commit_for_fix)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niomap: adjust read range correctly for non-block-aligned positions\n\niomap_adjust_read_range() assumes that the position and length passed in\nare block-aligned. This is not always the case however, as shown in the\nsyzbot generated case for erofs. This causes too many bytes to be\nskipped for uptodate blocks, which results in returning the incorrect\nposition and length to read in. If all the blocks are uptodate, this\nunderflows length and returns a position beyond the folio.\n\nFix the calculation to also take into account the block offset when\ncalculating how many bytes can be skipped for uptodate blocks."
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    "dateReserved": "2025-12-24T10:30:51.037Z",
    "dateUpdated": "2026-01-13T15:29:05.553Z",
    "state": "PUBLISHED"
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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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