CVE-2025-38584 padata: Fix pd UAF once and for all
A use-after-free race condition in the Linux kernel padata subsystem allows attackers to execute arbitrary code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-38584?
CVE-2025-38584 is a high-severity use after free vulnerability in Linux kernel, published on 19 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
padata: Fix pd UAF once and for all
There is a race condition/UAF in padata_reorder that goes back to the initial commit. A reference count is taken at the start of the process in padata_do_parallel, and released at the end in padata_serial_worker.
This reference count is (and only is) required for padata_replace to function correctly. If padata_replace is never called then there is no issue.
In the function padata_reorder which serves as the core of padata, as soon as padata is added to queue->serial.list, and the associated spin lock released, that padata may be processed and the reference count on pd would go away.
Fix this by getting the next padata before the squeue->serial lock is released.
In order to make this possible, simplify padata_reorder by only calling it once the next padata arrives.
Weakness: CWE-416
Which versions are affected by CVE-2025-38584?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38584?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-38584 being exploited?
There is no known exploitation of CVE-2025-38584 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-66518, AZL-71027, BELL-CVE-2025-38584, DEBIAN-CVE-2025-38584, GHSA-7848-x3wq-cg7m, ROOT-OS-DEBIAN-11-CVE-2025-38584 and 5 more.