---
id: CVE-2023-52942
title: 'cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask()

  It was found that the check to see if a partition could use up all
  the cpus from the parent cpuset i…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= f0af1bfc27b52a4d42510051154c61bd176a8f06 <
    a2ab7f2cf5ef8f0c6212a246e681d1fe358cec1f
  - >-
    Linux >= f0af1bfc27b52a4d42510051154c61bd176a8f06 <
    e5ae8803847b80fe9d744a3174abe2b7bfed222a
  - Linux 6.1
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:13:59.225297Z'
published: '2025-03-27'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:20:53.087Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-52942'
references:
  - url: 'https://git.kernel.org/stable/c/a2ab7f2cf5ef8f0c6212a246e681d1fe358cec1f'
  - url: 'https://git.kernel.org/stable/c/e5ae8803847b80fe9d744a3174abe2b7bfed222a'
tags:
  - cve.org
epss: 0.00228
epssPercentile: 0.13694
ingestedAt: '2026-11-05T22:38:31.751Z'
---

## Overview

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

cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask()

It was found that the check to see if a partition could use up all
the cpus from the parent cpuset in update_parent_subparts_cpumask()
was incorrect. As a result, it is possible to leave parent with no
effective cpu left even if there are tasks in the parent cpuset. This
can lead to system panic as reported in [1].

Fix this probem by updating the check to fail the enabling the partition
if parent's effective_cpus is a subset of the child's cpus_allowed.

Also record the error code when an error happens in update_prstate()
and add a test case where parent partition and child have the same cpu
list and parent has task. Enabling partition in the child will fail in
this case.

[1] https://www.spinics.net/lists/cgroups/msg36254.html

## Affected

- `Linux >= f0af1bfc27b52a4d42510051154c61bd176a8f06 < a2ab7f2cf5ef8f0c6212a246e681d1fe358cec1f`
- `Linux >= f0af1bfc27b52a4d42510051154c61bd176a8f06 < e5ae8803847b80fe9d744a3174abe2b7bfed222a`
- `Linux 6.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.