---
id: CVE-2023-54285
title: 'iomap: Fix possible overflow condition in iomap_write_delalloc_scan'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iomap: Fix possible overflow condition in iomap_write_delalloc_scan

  folio_next_index() returns an unsigned long value which left shifted
  by PAGE_SHIFT could possibly c…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 38be53c3fd7f4f4bd5de319a323d72f9f6beb16d <
    0c6cf409093f307ee05114f834516730c0da5b21
  - >-
    Linux >= f43dc4dc3eff028b5ddddd99f3a66c5a6bdd4e78 <
    5c281b0c5d18c8eeb1cfd5023f4adb153e6d1240
  - >-
    Linux >= f43dc4dc3eff028b5ddddd99f3a66c5a6bdd4e78 <
    eee2d2e6ea5550118170dbd5bb1316ceb38455fb
  - Linux >= 6.1.92 < 6.1.162
  - Linux 6.2
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-15T21:40:04.519325Z'
published: '2025-12-30'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T21:41:44.022Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-54285'
references:
  - url: 'https://git.kernel.org/stable/c/0c6cf409093f307ee05114f834516730c0da5b21'
  - url: 'https://git.kernel.org/stable/c/5c281b0c5d18c8eeb1cfd5023f4adb153e6d1240'
  - url: 'https://git.kernel.org/stable/c/eee2d2e6ea5550118170dbd5bb1316ceb38455fb'
tags:
  - cve.org
epss: 0.00179
epssPercentile: 0.06987
ingestedAt: '2026-10-15T22:48:25.437Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

iomap: Fix possible overflow condition in iomap_write_delalloc_scan

folio_next_index() returns an unsigned long value which left shifted
by PAGE_SHIFT could possibly cause an overflow on 32-bit system. Instead
use folio_pos(folio) + folio_size(folio), which does this correctly.

## Affected

- `Linux >= 38be53c3fd7f4f4bd5de319a323d72f9f6beb16d < 0c6cf409093f307ee05114f834516730c0da5b21`
- `Linux >= f43dc4dc3eff028b5ddddd99f3a66c5a6bdd4e78 < 5c281b0c5d18c8eeb1cfd5023f4adb153e6d1240`
- `Linux >= f43dc4dc3eff028b5ddddd99f3a66c5a6bdd4e78 < eee2d2e6ea5550118170dbd5bb1316ceb38455fb`
- `Linux >= 6.1.92 < 6.1.162`
- `Linux 6.2`

## Remediation

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