CVE-2025-21786

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/e7c16028a424dd35be1064a68fa318be4359310f ↗
• https://git.kernel.org/stable/c/835b69c868f53f959d4986bbecd561ba6f38e492 ↗
• https://git.kernel.org/stable/c/e76946110137703c16423baf6ee177b751a34b7e ↗