---
id: CVE-2025-68794
title: |-
  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
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 …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
published: '2026-01-13'
updated: '2026-08-27'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-68794'
references:
  - url: 'https://git.kernel.org/stable/c/12053695c8ef5410e8cc6c9ed4c0db9cd9c82b3e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/142194fb21afe964d2d194cab1fc357cbf87e899'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/275b37a1e5c2c8abd313e8075f6aec9a349f291b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7aa6bc3e8766990824f66ca76c19596ce10daf3e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/82b60ffbb532d919959702768dca04c3c0500ae5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b8c9f25fd84328c5fcc4f70c6d1e8f1d4787eaac'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ce20f49ac9194cf81a77f01d1c316d7c17ae753c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00588
epssPercentile: 0.45832
ingestedAt: '2026-08-27T14:02:52.898Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.