CVE-2025-38673 Revert "drm/gem-framebuffer: Use dma_buf from GEM object instance"
A null pointer dereference in the Linux kernel DRM subsystem allows local attackers to cause a system crash.
- 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-2025-38673?
CVE-2025-38673 is a medium-severity vulnerability in Linux kernel, published on 22 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:
Revert "drm/gem-framebuffer: Use dma_buf from GEM object instance"
This reverts commit cce16fcd7446dcff7480cd9d2b6417075ed81065.
The dma_buf field in struct drm_gem_object is not stable over the object instance's lifetime. The field becomes NULL when user space releases the final GEM handle on the buffer object. This resulted in a NULL-pointer deref.
Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer: Acquire internal references on GEM handles") only solved the problem partially. They especially don't work for buffer objects without a DRM framebuffer associated.
Hence, this revert to going back to using .import_attach->dmabuf.
v3: - cc stable
Weakness: CWE-476
Which versions are affected by CVE-2025-38673?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38673?
Apply the vendor's patch.
Is CVE-2025-38673 being exploited?
There is no known exploitation of CVE-2025-38673 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-38673, GHSA-5qx5-jpr4-rw99, ROOT-OS-UBUNTU-2204-CVE-2025-38673, ROOT-OS-UBUNTU-2404-CVE-2025-38673, UBUNTU-CVE-2025-38673.