CVE-2025-71140 media: mediatek: vcodec: Use spinlock for context list protection lock
A NULL pointer dereference in the MediaTek vcodec driver can cause a kernel crash when triggered by specific video decoding operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-71140?
CVE-2025-71140 is a vulnerability in Linux, published on 14 Jan 2026. 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:
media: mediatek: vcodec: Use spinlock for context list protection lock
Previously a mutex was added to protect the encoder and decoder context lists from unexpected changes originating from the SCP IP block, causing the context pointer to go invalid, resulting in a NULL pointer dereference in the IPI handler.
Turns out on the MT8173, the VPU IPI handler is called from hard IRQ context. This causes a big warning from the scheduler. This was first reported downstream on the ChromeOS kernels, but is also reproducible on mainline using Fluster with the FFmpeg v4l2m2m decoders. Even though the actual capture format is not supported, the affected code paths are triggered.
Since this lock just protects the context list and operations on it are very fast, it should be OK to switch to a spinlock.
Which versions are affected by CVE-2025-71140?
How do I fix CVE-2025-71140?
Apply the vendor's patch.
Is CVE-2025-71140 being exploited?
There is no known exploitation of CVE-2025-71140 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2025-71140, GHSA-fmmj-6v74-3cm2, ROOT-OS-DEBIAN-13-CVE-2025-71140, ROOT-OS-UBUNTU-2404-CVE-2025-71140, UBUNTU-CVE-2025-71140.