---
id: "CVE-2026-98669"
kind: "vulnerability"
aliases: ["CVE-2026-98669"]
title: "Linux kernel IIO: buffer teardown can race active mode claims on unregister"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["embedded", "iio", "linux-kernel", "runtime"]
not_affected_if: ["no-iio-devices"]
published_at: "2026-10-18T16:17:20+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:19:23+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98669", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel IIO: buffer teardown can race active mode claims on unregister

In the Linux kernel's Industrial I/O (IIO) subsystem, unregistering a device disables and deactivates its buffers without holding the mode lock, so buffer state can change while a buffer-mode claim is held. The sources do not describe a concrete attacker-reachable impact.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- Update to a Linux kernel release that includes the upstream commit 'iio: buffer: serialize buffer teardown with mode claims' (kernel version unknown from sources)

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98669

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

iio: buffer: serialize buffer teardown with mode claims

Buffer-mode claims hold mlock to guarantee that the device remains in
buffer mode until the claim is released. Normal buffer updates take
info_exist_lock followed by mlock in iio_update_buffers().

However, iio_device_unregister() disables and deactivates all buffers
without taking mlock. This can invalidate buffer state, including
active_scan_mask, while a buffer-mode claim is held.

Take mlock in iio_disable_all_buffers() so that unregister honors the
mode-claim lifetime guarantee. The info_exist_lock -> mlock ordering
matches iio_update_buffers().

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