CVE-2026-89941 iio: buffer: Make IIO DMA fence release RCU-safe
A use-after-free vulnerability in the Linux kernel's IIO DMA fence release mechanism allows attackers to potentially execute 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-2026-89941?
CVE-2026-89941 is a high-severity use after free vulnerability in Linux, published on 16 Sep 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:
iio: buffer: Make IIO DMA fence release RCU-safe
The `dma_fence` documentation states that if a custom release implementation is provided, the `dma_fence` object must be freed in an RCU-safe way. The current `iio_dma_fence` implementation uses `kfree()`, which might result in a use-after-free.
Remove the custom `release` implementation. This makes the DMA fence core fall back to `dma_fence_free()`, which calls `kfree_rcu()` on the fence. This requires that the fence be the first member of `struct iio_dma_fence`.
Using the default release method for extended DMA fence structures is a common pattern.
Which versions are affected by CVE-2026-89941?
How do I fix CVE-2026-89941?
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-2026-89941 being exploited?
There is no known exploitation of CVE-2026-89941 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89941, DEBIAN-CVE-2026-89941, GHSA-m3pj-6mpg-h767, UBUNTU-CVE-2026-89941.