---
id: CVE-2026-98677
title: 'iio: adc: ad_sigma_delta: fix use-after-free on unbind'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  iio: adc: ad_sigma_delta: fix use-after-free on unbind

  ad_sd_buffer_postenable() allocates sigma_delta->samples_buf with
  devm_krealloc() at runtime, so its devres entr…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b <
    84500ae0d976995a6870cb1dca2d124b6b2d6e5a
  - >-
    Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b <
    f20b94a7dc1ff9ade191ce839c984210fdbdc653
  - >-
    Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b <
    5663c72bf400231e90777982216797191887a6b9
  - >-
    Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b <
    9ee8306121495d2a25aa5d1bfd519f2748786b83
  - Linux 5.19
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:45:33.871Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98677'
references:
  - url: 'https://git.kernel.org/stable/c/84500ae0d976995a6870cb1dca2d124b6b2d6e5a'
  - url: 'https://git.kernel.org/stable/c/f20b94a7dc1ff9ade191ce839c984210fdbdc653'
  - url: 'https://git.kernel.org/stable/c/5663c72bf400231e90777982216797191887a6b9'
  - url: 'https://git.kernel.org/stable/c/9ee8306121495d2a25aa5d1bfd519f2748786b83'
tags:
  - cve.org
ingestedAt: '2026-10-18T16:47:32.531Z'
---

## Overview

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

iio: adc: ad_sigma_delta: fix use-after-free on unbind

ad_sd_buffer_postenable() allocates sigma_delta->samples_buf with
devm_krealloc() at runtime, so its devres entry sits after all
probe-time entries of the driver. devm resources are released in
reverse allocation order, which means unbind frees samples_buf before
iio_device_unregister() disables the buffers and detaches the trigger
pollfunc. The data ready IRQ is still enabled at that point, so
ad_sd_trigger_handler() can still run and memcpy() incoming samples
into the freed samples_buf.

Fix this by preallocating the buffer in
devm_ad_sd_setup_buffer_and_trigger(), before the triggered buffer and
the IRQ are set up, so it is freed only after iio_device_unregister()
has drained the trigger handler via free_irq(). Size it for the worst
case of all sequencer slots being active; ad_sd_validate_scan_mask()
already caps the number of active channels at num_slots.

This issue was found by an in-house static analysis tool.

## Affected

- `Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b < 84500ae0d976995a6870cb1dca2d124b6b2d6e5a`
- `Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b < f20b94a7dc1ff9ade191ce839c984210fdbdc653`
- `Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b < 5663c72bf400231e90777982216797191887a6b9`
- `Linux >= 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b < 9ee8306121495d2a25aa5d1bfd519f2748786b83`
- `Linux 5.19`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.