CVE-2023-53997 thermal: of: fix double-free on unregistration
A double-free vulnerability in the Linux kernel thermal subsystem allows attackers to cause denial of service or potentially execute code.
- 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-2023-53997?
CVE-2023-53997 is a high-severity use after free vulnerability in Linux, published on 24 Dec 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:
thermal: of: fix double-free on unregistration
Since commit 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone parameters structure"), thermal_zone_device_register() allocates a copy of the tzp argument and frees it when unregistering, so thermal_of_zone_register() now ends up leaking its original tzp and double-freeing the tzp copy. Fix this by locating tzp on stack instead.
Which versions are affected by CVE-2023-53997?
How do I fix CVE-2023-53997?
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-2023-53997 being exploited?
There is no known exploitation of CVE-2023-53997 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-53997, DEBIAN-CVE-2023-53997, GHSA-hjrg-jf9q-4c95, UBUNTU-CVE-2023-53997.