cpu/hotplug: Don't offline the last non-isolated CPU

Description

In the Linux kernel, the following vulnerability has been resolved: cpu/hotplug: Don't offline the last non-isolated CPU If a system has isolated CPUs via the "isolcpus=" command line parameter, then an attempt to offline the last housekeeping CPU will result in a WARN_ON() when rebuilding the scheduler domains and a subsequent panic due to and unhandled empty CPU mas in partition_sched_domains_locked(). cpuset_hotplug_workfn() rebuild_sched_domains_locked() ndoms = generate_sched_domains(&doms, &attr); cpumask_and(doms[0], top_cpuset.effective_cpus, housekeeping_cpumask(HK_FLAG_DOMAIN)); Thus results in an empty CPU mask which triggers the warning and then the subsequent crash: WARNING: CPU: 4 PID: 80 at kernel/sched/topology.c:2366 build_sched_domains+0x120c/0x1408 Call trace: build_sched_domains+0x120c/0x1408 partition_sched_domains_locked+0x234/0x880 rebuild_sched_domains_locked+0x37c/0x798 rebuild_sched_domains+0x30/0x58 cpuset_hotplug_workfn+0x2a8/0x930 Unable to handle kernel paging request at virtual address fffe80027ab37080 partition_sched_domains_locked+0x318/0x880 rebuild_sched_domains_locked+0x37c/0x798 Aside of the resulting crash, it does not make any sense to offline the last last housekeeping CPU. Prevent this by masking out the non-housekeeping CPUs when selecting a target CPU for initiating the CPU unplug operation via the work queue.

Scores

EPSS (exploitation in 30 days)

0.24% · top 85% of all CVEs (7 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Weakness

• CWE-617 (opens in a new tab)All about CWE-617 and its CVEs

Affected products

• Linux · Linux

  • affected fea9dd8653ff39ce383c54e747bde4c39289b4ad – < 3410b702354702b500bde10e3cc1f9db8731d908
  • affected 07f9e0c9987bf1c4ef57611ad2f789ba68978102 – < 335a47ed71e332c82339d1aec0c7f6caccfcda13
  • affected 2b8272ff4a70b866106ae13c36be7ecbef5d5da2 – < 3073f6df783d9d75f7f69f73e16c7ef85d6cfb63
  • affected 2b8272ff4a70b866106ae13c36be7ecbef5d5da2 – < 38685e2a0476127db766f81b1c06019ddc4c9ffa
  • affected 9734e4c0c470258c32b6aa5ea7ef8a86506c0909
  • affected 6.1.53 – < 6.1.64
  • affected 6.5.3 – < 6.5.13
  • affected 6.4.16 – < 6.5

• Linux · Linux

  • affected 6.6
  • unaffected < 6.6
  • unaffected 6.1.64 – ≤ 6.1.*
  • unaffected 6.5.13 – ≤ 6.5.*
  • unaffected 6.6.3 – ≤ 6.6.*
  • unaffected 6.7 – ≤ *

References (4)

• https://git.kernel.org/stable/c/3410b702354702b500bde10e3cc1f9db8731d908 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/335a47ed71e332c82339d1aec0c7f6caccfcda13 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/3073f6df783d9d75f7f69f73e16c7ef85d6cfb63 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/38685e2a0476127db766f81b1c06019ddc4c9ffa (opens in a new tab)x_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2023-52831](https://trackcve.app/badge/CVE-2023-52831.svg)](https://trackcve.app/cve/CVE-2023-52831)

Record last updated 23 May 2026, 15:27 UTC.