CVE-2023-54271

System crash via uninitialized block-cgroup policy data

Published Dec 30, 2025 · Updated Dec 30, 2025

Race condition in the Linux kernel blk-cgroup subsystem allows local users to crash the system through concurrent cgroup writes. blkcg_activate_policy installs blkg_policy_data before ioc_pd_init initializes iocg->ioc, allowing ioc_weight_write to race into a NULL pointer. Local access to writable cgroup I/O control files and an enabled io controller is required; the reported consequence is a kernel crash.

CVSS severity4.7
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux kernel blk-cgroup subsystem allows local users to crash the system through concurrent cgroup writes. blkcg_activate_policy installs blkg_policy_data before ioc_pd_init initializes iocg->ioc, allowing ioc_weight_write to race into a NULL pointer. Local access to writable cgroup I/O control files and an enabled io controller is required; the reported consequence is a kernel crash.

The record

CVE
CVE-2023-54271
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.4
  2. Affected versionversion=9d179b865449b351ad5cb76dbea480c9170d4a27 <7d63c6f9765339dcfc34b7365ced7c518012e4fe
  3. Affected versionversion=9d179b865449b351ad5cb76dbea480c9170d4a27 <e39ef7880d1057b2ebcdb013405f4d84a257db23
  4. Affected versionversion=9d179b865449b351ad5cb76dbea480c9170d4a27 <ec14a87ee1999b19d8b7ed0fa95fea80644624ae

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.4; version=9d179b865449b351ad5cb76dbea480c9170d4a27 <7d63c6f9765339dcfc34b7365ced7c518012e4fe; version=9d179b865449b351ad5cb76dbea480c9170d4a27 <e39ef7880d1057b2ebcdb013405f4d84a257db23; version=9d179b865449b351ad5cb76dbea480c9170d4a27 <ec14a87ee1999b19d8b7ed0fa95fea80644624ae

Published CVSS scores

4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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