---
id: CVE-2021-44879
title: >-
  In gc_data_segment in fs/f2fs/gc.c in the Linux kernel before 5.16.3, special
  files are not considered, leading to a move_data_page NULL pointer
  dereference.
summary: >-
  In gc_data_segment in fs/f2fs/gc.c in the Linux kernel before 5.16.3, special
  files are not considered, leading to a move_data_page NULL pointer
  dereference.
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: linux
product: linux_kernel
affected:
  - linux_kernel < 5.16.3
patched:
  - linux_kernel 5.16.3
published: '2022-02-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T12:17:16.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-44879'
references:
  - url: 'https://bugzilla.kernel.org/show_bug.cgi?id=215231'
    label: cve@mitre.org
  - url: 'https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.3'
    label: cve@mitre.org
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9056d6489f5a41cfbb67f719d2c0ce61ead72d9f
    label: cve@mitre.org
  - url: 'https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html'
    label: cve@mitre.org
  - url: 'https://lists.debian.org/debian-lts-announce/2024/01/msg00005.html'
    label: cve@mitre.org
  - url: >-
      https://lore.kernel.org/linux-f2fs-devel/20211206144421.3735-3-chao%40kernel.org/T/
    label: cve@mitre.org
  - url: 'https://bugzilla.kernel.org/show_bug.cgi?id=215231'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.3'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9056d6489f5a41cfbb67f719d2c0ce61ead72d9f
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2024/01/msg00005.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lore.kernel.org/linux-f2fs-devel/20211206144421.3735-3-chao%40kernel.org/T/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-613116.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-794697.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-831302.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.01229
epssPercentile: 0.6813
ingestedAt: '2026-10-14T12:29:10.828Z'
---

## Overview

In gc_data_segment in fs/f2fs/gc.c in the Linux kernel before 5.16.3, special files are not considered, leading to a move_data_page NULL pointer dereference.

## Affected

- `linux_kernel < 5.16.3`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.16.3`