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

workqueue: Put the pwq after detaching the rescuer from the pool

The commit 68f83057b913("workqueue: Reap workers via kthread_stop() and
remove detach_completion") adds code to reap the normal workers but
mistakenly does not handle the rescuer and also removes the code waiting
for the rescuer in put_unbound_pool(), which caused a use-after-free bug
reported by Cheung Wall.

To avoid the use-after-free bug, the pool’s reference must be held until
the detachment is complete. Therefore, move the code that puts the pwq
after detaching the rescuer from the pool.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.0003.

Exploitation none

Automatable no

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
68f83057b913467a999e1bf9e0da6a119668f769 affected
< e7c16028a424dd35be1064a68fa318be4359310f
68f83057b913467a999e1bf9e0da6a119668f769 affected
< 835b69c868f53f959d4986bbecd561ba6f38e492
68f83057b913467a999e1bf9e0da6a119668f769 affected
< e76946110137703c16423baf6ee177b751a34b7e
Linux Linux affected
Version Status Constraints
6.11 affected
—
0 unaffected
< 6.11
6.12.16 unaffected
≤ 6.12.*
6.13.4 unaffected
≤ 6.13.*
6.14 unaffected
≤ *

Configuration 1 [-]

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

No data.

No data.

Project Subscriptions

Vendors Products
Linux Subscribe
Linux Kernel Subscribe
Advisories
Source ID Title
EUVD EUVD EUVD-2025-5141 In the Linux kernel, the following vulnerability has been resolved: workqueue: Put the pwq after detaching the rescuer from the pool The commit 68f83057b913("workqueue: Reap workers via kthread_stop() and remove detach_completion") adds code to reap the normal workers but mistakenly does not handle the rescuer and also removes the code waiting for the rescuer in put_unbound_pool(), which caused a use-after-free bug reported by Cheung Wall. To avoid the use-after-free bug, the pool’s reference must be held until the detachment is complete. Therefore, move the code that puts the pwq after detaching the rescuer from the pool.
Ubuntu USN Ubuntu USN USN-7521-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7521-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7521-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7703-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7703-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7703-3 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7703-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7719-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7737-1 Linux kernel (Azure) vulnerabilities
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/835b69c868f53f959d4986bbecd561ba6f38e492 cve-icon cve-icon
https://git.kernel.org/stable/c/e76946110137703c16423baf6ee177b751a34b7e cve-icon cve-icon
https://git.kernel.org/stable/c/e7c16028a424dd35be1064a68fa318be4359310f cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025022608-CVE-2025-21786-f31d@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-21786 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-21786 cve-icon
History

Fri, 21 Mar 2025 16:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel

Tue, 04 Mar 2025 03:45:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Fri, 28 Feb 2025 02:00:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Moderate

Thu, 27 Feb 2025 19:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Thu, 27 Feb 2025 02:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: workqueue: Put the pwq after detaching the rescuer from the pool The commit 68f83057b913("workqueue: Reap workers via kthread_stop() and remove detach_completion") adds code to reap the normal workers but mistakenly does not handle the rescuer and also removes the code waiting for the rescuer in put_unbound_pool(), which caused a use-after-free bug reported by Cheung Wall. To avoid the use-after-free bug, the pool’s reference must be held until the detachment is complete. Therefore, move the code that puts the pwq after detaching the rescuer from the pool.
Title workqueue: Put the pwq after detaching the rescuer from the pool
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T07:21:13.261Z

Reserved: 2024-12-29T08:45:45.765Z

Link: CVE-2025-21786

cve-icon Vulnrichment

Updated: 2025-02-27T18:14:16.659Z

cve-icon NVD

Status : Analyzed

Published: 2025-02-27T03:15:19.450

Modified: 2025-03-21T15:43:17.480

Link: CVE-2025-21786

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-02-27T00:00:00Z

Links: CVE-2025-21786 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses