---
id: "CVE-2026-98668"
kind: "vulnerability"
aliases: ["CVE-2026-98668"]
title: "Linux kernel IIO: unaligned buffer push leaks uninitialized heap memory"
severity: "low"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["embedded", "iio-sensors", "linux-kernel", "runtime"]
not_affected_if: ["no-iio-drivers"]
published_at: "2026-10-18T16:17:20+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:19:25+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98668", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel IIO: unaligned buffer push leaks uninitialized heap memory

In the Linux kernel IIO subsystem, the unaligned timestamp push path could send uninitialized heap memory to userspace when data is not a multiple of 8 bytes and timestamps are enabled. The fix zeroes the bounce buffer so extra bytes are cleared.

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

## How to check

- Run `uname -r` and compare against the kernel version that carries the upstream fix for CVE-2026-98668 (unknown from the sources).
- Check whether IIO sensor drivers are loaded with `lsmod | grep -i iio`; unknown from the sources whether a specific driver is required.

## Fix

- Update the Linux kernel to a release that includes the upstream commit adding __GFP_ZERO to the devm_krealloc() in iio_push_to_buffers_with_ts_unaligned(); the exact fixed version is unknown from the sources.

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98668

## From the sources

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

iio: buffer: Ensure bounce buffer used for unaligned case is zeroed.

iio_push_to_buffers_with_ts_unaligned() leaks uninitialized heap memory
to userspace if the data passed in is not a multiple of 8 bytes and the
timestamp is enabled. Specify __GFP_ZERO for the devm_krealloc()
to ensure any extra space is cleared.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_