CVE-2023-53636 clk: microchip: fix potential UAF in auxdev release callback
A use-after-free vulnerability in the Linux kernel's Microchip clock driver allows attackers to potentially 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-2023-53636?
CVE-2023-53636 is a high-severity use after free vulnerability in Linux kernel, published on 7 Oct 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:
clk: microchip: fix potential UAF in auxdev release callback
Similar to commit 1c11289b34ab ("peci: cpu: Fix use-after-free in adev_release()"), the auxiliary device is not torn down in the correct order. If auxiliary_device_add() fails, the release callback will be called twice, resulting in a UAF. Due to timing, the auxdev code in this driver "took inspiration" from the aforementioned commit, and thus its bugs too!
Moving auxiliary_device_uninit() to the unregister callback instead avoids the issue.
Weakness: CWE-416
Which versions are affected by CVE-2023-53636?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53636?
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-2023-53636 being exploited?
There is no known exploitation of CVE-2023-53636 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53636, DEBIAN-CVE-2023-53636, GHSA-w939-vjpg-j262, UBUNTU-CVE-2023-53636.