PT-2025-54100 · Linux+2 · Linux Kernel+2

Published

2023-01-01

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Updated

2026-04-20

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CVE-2023-54271

CVSS v2.0

4.6

Medium

VectorAV:L/AC:L/Au:S/C:N/I:N/A:C
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description The Linux kernel contained a flaw in the block cgroup (blk-cgroup) subsystem. Specifically, a NULL pointer dereference could occur due to blkg policy data being installed before initialization. This issue stemmed from a race condition where blkcg activate policy() allocated and installed policy data structures before they were fully initialized, potentially leading to a crash when accessed by other functions like ioc weight write(). The root cause was the order in which policy data was allocated, initialized, and online, creating a window for the race condition. A patch was applied to address this by initializing and onlining policy data for each block group individually while holding the blkcg->lock, ensuring that a block group is always fully initialized and online.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

NULL Pointer Dereference

Weakness Enumeration

Related Identifiers

BDU:2026-01198
CVE-2023-54271
RHSA-2024:9315
SUSE-SU-2026:0263-1
SUSE-SU-2026:0278-1
SUSE-SU-2026:0281-1
SUSE-SU-2026:0293-1
SUSE-SU-2026:0315-1
SUSE-SU-2026:0316-1
SUSE-SU-2026:0317-1
SUSE-SU-2026:0411-1
SUSE-SU-2026:0617-1
SUSE-SU-2026:20477-1
SUSE-SU-2026:20498-1
SUSE-SU-2026:20845-1
SUSE-SU-2026:20876-1

Affected Products

Debian
Linux Kernel
Red Hat