---
id: CVE-2025-38478
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  comedi: Fix initialization of data for instructions that write to subdevice

  Some Comedi subdevice instruction handlers are known to access
  instruction data elements be…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  comedi: Fix initialization of data for instructions that write to subdevice

  Some Comedi subdevice instruction handlers are known to access
  instruction data elements be…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-908
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 2.6.29, < 5.4.297'
  - 'linux_kernel >= 5.5, < 5.10.241'
  - 'linux_kernel >= 5.11, < 5.15.190'
  - 'linux_kernel >= 5.16, < 6.1.147'
  - 'linux_kernel >= 6.2, < 6.6.100'
  - 'linux_kernel >= 6.7, < 6.12.40'
  - 'linux_kernel >= 6.13, < 6.15.8'
  - linux_kernel = 6.16
  - debian_linux = 11.0
patched:
  - linux_kernel 6.15.8
published: '2025-07-28'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:18:42.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-38478'
references:
  - url: 'https://git.kernel.org/stable/c/020eed5681d0f9bced73970368078a92d6cfaa9c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/13e4d9038a1e869445a996a3f604a84ef52fe8f4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/46d8c744136ce2454aa4c35c138cc06817f92b8e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/673ee92bd2d31055bca98a1d96b653f5284289c4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6f38c6380c3b38a05032b8881e41137385a6ce02'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c42116dc70af6664526f7aa82cf937824ab42649'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d3436638738ace8f101af7bdee2eae1bc38e9b29'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fe8713fb4e4e82a4f91910d9a41bf0613e69a0b9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
epss: 0.00179
epssPercentile: 0.07396
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:50:50.290792Z'
ingestedAt: '2026-10-15T22:48:25.509Z'
---

## Overview

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

comedi: Fix initialization of data for instructions that write to subdevice

Some Comedi subdevice instruction handlers are known to access
instruction data elements beyond the first `insn->n` elements in some
cases.  The `do_insn_ioctl()` and `do_insnlist_ioctl()` functions
allocate at least `MIN_SAMPLES` (16) data elements to deal with this,
but they do not initialize all of that.  For Comedi instruction codes
that write to the subdevice, the first `insn->n` data elements are
copied from user-space, but the remaining elements are left
uninitialized.  That could be a problem if the subdevice instruction
handler reads the uninitialized data.  Ensure that the first
`MIN_SAMPLES` elements are initialized before calling these instruction
handlers, filling the uncopied elements with 0.  For
`do_insnlist_ioctl()`, the same data buffer elements are used for
handling a list of instructions, so ensure the first `MIN_SAMPLES`
elements are initialized for each instruction that writes to the
subdevice.

## Affected

- `linux_kernel >= 2.6.29, < 5.4.297`
- `linux_kernel >= 5.5, < 5.10.241`
- `linux_kernel >= 5.11, < 5.15.190`
- `linux_kernel >= 5.16, < 6.1.147`
- `linux_kernel >= 6.2, < 6.6.100`
- `linux_kernel >= 6.7, < 6.12.40`
- `linux_kernel >= 6.13, < 6.15.8`
- `linux_kernel = 6.16`
- `debian_linux = 11.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.15.8`