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.
Advisories

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Fixes

Solution

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Workaround

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History

Tue, 13 Jan 2026 15:45:00 +0000

Type Values Removed Values Added
Description 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.
Title iomap: adjust read range correctly for non-block-aligned positions
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-01-13T15:29:05.553Z

Reserved: 2025-12-24T10:30:51.037Z

Link: CVE-2025-68794

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-01-13T16:16:01.310

Modified: 2026-01-13T16:16:01.310

Link: CVE-2025-68794

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.