CVE-2025-21995 drm/sched: Fix fence reference count leak
A reference count leak in the Linux kernel's DRM scheduler can lead to memory exhaustion and denial of service when entity cleanup fails.
- 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-2025-21995?
CVE-2025-21995 is a medium-severity memory corruption vulnerability in Linux kernel, published on 3 Apr 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:
drm/sched: Fix fence reference count leak
The last_scheduled fence leaks when an entity is being killed and adding the cleanup callback fails.
Decrement the reference count of prev when dma_fence_add_callback() fails, ensuring proper balance.
[phasta: add git tag info for stable kernel]
Which versions are affected by CVE-2025-21995?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21995?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-21995 being exploited?
There is no known exploitation of CVE-2025-21995 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-60264, BELL-CVE-2025-21995, DEBIAN-CVE-2025-21995, GHSA-jwm2-2q27-v4vh, ROOT-OS-UBUNTU-2404-CVE-2025-21995, UBUNTU-CVE-2025-21995.