---
id: CVE-2025-71142
title: 'cpuset: fix warning when disabling remote partition'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  cpuset: fix warning when disabling remote partition

  A warning was triggered as follows:

  WARNING: kernel/cgroup/cpuset.c:1651 at remote_partition_disable+0xf7/0x110
  RI…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 93f045741dac64facf90c2216f9a1d0876d122c4 <
    71953da7c979983917a4597bcad2c1ea6b8cc226
  - >-
    Linux >= f62a5d39368e34a966c8df63e1f05eed7fe9c5de <
    5d8b9d38a7676be7bb5e7d57f92156a98dab39fb
  - >-
    Linux >= f62a5d39368e34a966c8df63e1f05eed7fe9c5de <
    aa7d3a56a20f07978d9f401e13637a6479b13bd0
  - Linux 6.15
published: '2026-01-14'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T11:58:09.697Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-71142'
references:
  - url: 'https://git.kernel.org/stable/c/71953da7c979983917a4597bcad2c1ea6b8cc226'
  - url: 'https://git.kernel.org/stable/c/5d8b9d38a7676be7bb5e7d57f92156a98dab39fb'
  - url: 'https://git.kernel.org/stable/c/aa7d3a56a20f07978d9f401e13637a6479b13bd0'
tags:
  - cve.org
epss: 0.00132
epssPercentile: 0.02247
ingestedAt: '2026-09-14T15:23:07.459Z'
---

## Overview

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

cpuset: fix warning when disabling remote partition

A warning was triggered as follows:

WARNING: kernel/cgroup/cpuset.c:1651 at remote_partition_disable+0xf7/0x110
RIP: 0010:remote_partition_disable+0xf7/0x110
RSP: 0018:ffffc90001947d88 EFLAGS: 00000206
RAX: 0000000000007fff RBX: ffff888103b6e000 RCX: 0000000000006f40
RDX: 0000000000006f00 RSI: ffffc90001947da8 RDI: ffff888103b6e000
RBP: ffff888103b6e000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88810b2e2728 R12: ffffc90001947da8
R13: 0000000000000000 R14: ffffc90001947da8 R15: ffff8881081f1c00
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f55c8bbe0b2 CR3: 000000010b14c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 update_prstate+0x2d3/0x580
 cpuset_partition_write+0x94/0xf0
 kernfs_fop_write_iter+0x147/0x200
 vfs_write+0x35d/0x500
 ksys_write+0x66/0xe0
 do_syscall_64+0x6b/0x390
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f55c8cd4887

Reproduction steps (on a 16-CPU machine):

        # cd /sys/fs/cgroup/
        # mkdir A1
        # echo +cpuset > A1/cgroup.subtree_control
        # echo "0-14" > A1/cpuset.cpus.exclusive
        # mkdir A1/A2
        # echo "0-14" > A1/A2/cpuset.cpus.exclusive
        # echo "root" > A1/A2/cpuset.cpus.partition
        # echo 0 > /sys/devices/system/cpu/cpu15/online
        # echo member > A1/A2/cpuset.cpus.partition

When CPU 15 is offlined, subpartitions_cpus gets cleared because no CPUs
remain available for the top_cpuset, forcing partitions to share CPUs with
the top_cpuset. In this scenario, disabling the remote partition triggers
a warning stating that effective_xcpus is not a subset of
subpartitions_cpus. Partitions should be invalidated in this case to
inform users that the partition is now invalid(cpus are shared with
top_cpuset).

To fix this issue:
1. Only emit the warning only if subpartitions_cpus is not empty and the
   effective_xcpus is not a subset of subpartitions_cpus.
2. During the CPU hotplug process, invalidate partitions if
   subpartitions_cpus is empty.

## Affected

- `Linux >= 93f045741dac64facf90c2216f9a1d0876d122c4 < 71953da7c979983917a4597bcad2c1ea6b8cc226`
- `Linux >= f62a5d39368e34a966c8df63e1f05eed7fe9c5de < 5d8b9d38a7676be7bb5e7d57f92156a98dab39fb`
- `Linux >= f62a5d39368e34a966c8df63e1f05eed7fe9c5de < aa7d3a56a20f07978d9f401e13637a6479b13bd0`
- `Linux 6.15`

## Remediation

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