CVE-2025-21786 Details
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.
A use-after-free vulnerability has been identified in the Linux kernel's workqueue implementation. This issue arises when the rescuer is detached from the pool, leading to a premature release of a reference, which can be exploited. The vulnerability was introduced by a commit that reaped normal workers but failed to properly manage the rescuer, removing the necessary synchronization that prevented the use-after-free condition.
The vulnerability has been addressed in the Linux kernel. Users should upgrade to the latest version where this issue has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Feb 27, 2025References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/835b69c868f53f959d4986bbecd561ba6f38e492 | kernel.org | Patch |
| https://git.kernel.org/stable/c/e76946110137703c16423baf6ee177b751a34b7e | kernel.org | Patch |
| https://git.kernel.org/stable/c/e7c16028a424dd35be1064a68fa318be4359310f | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-416 | Use After Free | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | < 6.12.16 >= 6.13, < 6.13.4 |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Mar 21, 2025 | Initial Analysis | [email protected] |
| Feb 27, 2025 | CVE Modified | CISA-ADP |
| Feb 27, 2025 | New CVE Received | kernel.org |