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Fencer Intel
medium 5.5

CVE-2020-8992 json

ext4_protect_reserved_inode in fs/ext4/block_validity.c in the Linux kernel through 5.5.3 allows attackers to cause a denial of service (so…

published 6y ago modified 4mo ago also EUVD-2020-29822

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

Summary

ext4_protect_reserved_inode in fs/ext4/block_validity.c in the Linux kernel through 5.5.3 allows attackers to cause a denial of service (soft lockup) via a crafted journal size.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.5.13-1

debian advisories DEBIAN-CVE-2020-8992

  • linux Ubuntu 16.04 LTS 4.4.0-185.215
  • linux Ubuntu 18.04 LTS 4.15.0-96.97
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1110.121
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1065.69
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1060.64
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-96.97~16.04.1
  • linux-hwe Ubuntu 18.04 LTS 5.3.0-51.44~18.04.2
  • linux-kvm Ubuntu 16.04 LTS 4.4.0-1076.83

ubuntu advisories UBUNTU-CVE-2020-8992

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-syms SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-source SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-default SLES for SAP 15, SLES 15-LTSS, SLE Live Patching 15 +3 more 4.12.14-150.52.1
  • kernel-vanilla SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-obs-build SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-syms SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 4.4.121-92.129.1
  • kernel-source SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 4.4.121-92.129.1
  • kernel-default SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +2 more 4.4.121-92.129.1

suse advisories SUSE-SU-2020:1663-1SUSE-SU-2020:1255-1SUSE-SU-2020:1275-1SUSE-SU-2020:0688-1SUSE-SU-2020:0667-1SUSE-SU-2020:0649-1

  • kernel-syms openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-obs-qa openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-source openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-default openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-vanilla openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-kvmsmall openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-obs-build openSUSE Leap 15.1 4.12.14-lp151.28.40.1

opensuse advisories openSUSE-SU-2020:0336-1

Is CVE-2020-8992 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2020-8992 updated cvss 5.5

kernel: soft lockup via a crafted journal size in ext4_protect_reserved_inode in fs/ext4/block_validity.c

  • Red Hat Enterprise Linux 5 kernel 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, kernel-alt, python-perf, +9 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    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

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.9 AV:L/AC:L/Au:N/C:N/I:N/A:C

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-834 Excessive Iteration
Technology feeds

References

Sources

Fencer Intel 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.