---
id: CVE-2026-89840
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  f2fs: validate MOVE_RANGE destination size

  F2FS_IOC_MOVE_RANGE checks the source range, but not the destination end
  before updating i_size
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  f2fs: validate MOVE_RANGE destination size

  F2FS_IOC_MOVE_RANGE checks the source range, but not the destination end
  before updating i_size. A source hole can expose th…
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'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4dd6f977fc778e5a0da604e5f8cb2f36d163d27b <
    dcae1eeda53149f219dd6af93b3083b7271c1c63
  - >-
    Linux >= 4dd6f977fc778e5a0da604e5f8cb2f36d163d27b <
    e533889fc26aea0cd83c90327063f272061dd820
  - Linux 4.8
published: '2026-09-16'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T14:17:27.507'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89840'
references:
  - url: 'https://git.kernel.org/stable/c/db13064669526494cd78ba3a4394063b740e940c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/dcae1eeda53149f219dd6af93b3083b7271c1c63'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e533889fc26aea0cd83c90327063f272061dd820'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00158
epssPercentile: 0.0533
ingestedAt: '2026-09-16T10:53:53.997Z'
---

## Overview

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

f2fs: validate MOVE_RANGE destination size

F2FS_IOC_MOVE_RANGE checks the source range, but not the destination end
before updating i_size. A source hole can expose this: __clone_blkaddrs()
skips NULL_ADDR entries and returns success, so the caller can still extend
the destination inode with unchecked pos_out + len.

Reject destination overflow and use inode_newsize_ok() before extending
the destination inode.

## Remediation

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