Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2023-53421 — kernel

🟡 CVSS 5.5 — Medium ✅ No Known Exploit NVD
5.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()

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

blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()

When blkg_alloc() is called to allocate a blkcg_gq structure

with the associated blkg_iostat_set's, there are 2 fields within

blkg_iostat_set that requires proper initialization - blkg & sync.

The former field was introduced by commit 3b8cc6298724 ("blk-cgroup:

Optimize blkcg_rstat_flush()") while the later one was introduced by

commit f73316482977 ("blk-cgroup: reimplement basic IO stats using

cgroup rstat").

Unfortunately those fields in the blkg_iostat_set's are not properly

re-initialized when they are cleared in v1's blkcg_reset_stats(). This

can lead to a kernel panic due to NULL pointer access of the blkg

pointer. The missing initialization of sync is less problematic and

can be a problem in a debug kernel due to missing lockdep initialization.

Fix these problems by re-initializing them after memory clearing.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: None.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

CVE-2023-53421 is recorded against 2 packages.

  • kernel (from 6.4.0 up to 6.4.4)
  • linux-kernel (from 6.4 up to 6.4.4)

Timeline and source

Published on 18 September 2025 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

Other advisories for this package

kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:

Details

Severity Medium
CVSS Score 5.5
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-09-18
Updated 2026-08-20
Modified 2026-08-12

Affected Packages

Software From version Fixed in
kernel 6.4.0 6.4.4
linux-kernel 6.4 6.4.4

Similar Threats

Vulnerability Monitoring

Track new vulnerabilities in kernel

CVE-2023-53421 is rated CVSS 5.5 Medium. BotEraser monitors your WordPress installation and notifies you when software you use appears in our vulnerability database.

Set Up Free Alerts →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2023
✓