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Fencer Vulns
medium 5.5

CVE-2021-44879 json

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 po…

published 2022-02-13 4 y ago modified 2026-10-14 25 d ago also EUVD-2021-31680

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

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.

Patch / fix

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem V1.1
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • linux Debian 14, Debian 13, Debian 12 5.16.7-1

debian advisories DEBIAN-CVE-2021-44879

  • linux Ubuntu 20.04 LTS 5.4.0-173.191
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1120.130
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1124.133
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1067.72
  • linux-iot Ubuntu 20.04 LTS 5.4.0-1032.33
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1108.115
  • linux-azure Ubuntu 20.04 LTS 5.4.0-1126.133
  • linux-gkeop Ubuntu 20.04 LTS 5.4.0-1087.91

ubuntu advisories UBUNTU-CVE-2021-44879

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-azure SLE Module for Public Cloud 15 SP4, openSUSE Leap 15.4 5.14.21-150400.14.7.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP4, openSUSE Leap 15.4 5.14.21-150400.14.7.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP4, openSUSE Leap 15.4 5.14.21-150400.14.7.1
  • dtb-aarch64 openSUSE Leap 15.4 5.14.21-150400.24.11.1
  • kernel-64kb SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 5.14.21-150400.24.11.1
  • kernel-syms SLE Module for Development Tools 15 SP4, openSUSE Leap 15.4 5.14.21-150400.24.11.1
  • kernel-obs-qa openSUSE Leap 15.4 5.14.21-150400.24.11.1
  • kernel-source SLE Module for Development Tools 15 SP4, SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 5.14.21-150400.24.11.1

suse advisories SUSE-SU-2022:2615-1SUSE-SU-2022:2520-1SUSE-SU-2022:1257-1SUSE-SU-2022:0765-1SUSE-SU-2022:1039-1SUSE-SU-2022:1038-1

  • dtb-aarch64 openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-64kb openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-syms openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-obs-qa openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-source openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-default openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-preempt openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-kvmsmall openSUSE Leap 15.3 5.3.18-150300.59.60.4

opensuse advisories openSUSE-SU-2022:1039-1openSUSE-SU-2022:1037-1openSUSE-SU-2022:0768-1

  • kernel CBL-Mariner 2.0 5.15.26.1-1

azure linux advisories AZL-8577

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-44879 updated cvss 5.5

kernel: NULL pointer dereference in folio_mark_dirty() via a crafted f2fs image

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-25-226-15 updated

Siemens SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family
    not affected

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-23-348-10 updated cvss 5.5

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-23-166-10 updated cvss 5.5

Siemens SIMATIC S7-1500 TM MFP BIOS

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-23-166-11 updated cvss 5.5

Siemens SIMATIC S7-1500 TM MFP Linux Kernel

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

1.48% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=215231 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Affected products

  • Siemens RUGGEDCOM RST2428P
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family
  • Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.