---
id: CVE-2025-38006
title: 'net: mctp: Don''t access ifa_index when missing'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: mctp: Don't access ifa_index when missing

  In mctp_dump_addrinfo, ifa_index can be used to filter interfaces, but
  only when the struct ifaddrmsg is provided. Other…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d <
    8ef7b3f0db69e2f4a80be351f6aee9a4c2332ef9
  - >-
    Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d <
    d22efcd246a7688599eefcf8e5c7985a3854ef5d
  - >-
    Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d <
    acab78ae12c7fefb4f3bfe22e00770a5faa42724
  - >-
    Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d <
    d4d1561d17eb72908e4489c0900d96e0484fac20
  - >-
    Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d <
    24fa213dffa470166ec014f979f36c6ff44afb45
  - >-
    Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d <
    f11cf946c0a92c560a890d68e4775723353599e1
  - Linux 5.15
published: '2025-06-18'
updated: '2026-10-30'
sourceUpdated: '2026-10-30T12:21:31.744Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-38006'
references:
  - url: 'https://git.kernel.org/stable/c/8ef7b3f0db69e2f4a80be351f6aee9a4c2332ef9'
  - url: 'https://git.kernel.org/stable/c/d22efcd246a7688599eefcf8e5c7985a3854ef5d'
  - url: 'https://git.kernel.org/stable/c/acab78ae12c7fefb4f3bfe22e00770a5faa42724'
  - url: 'https://git.kernel.org/stable/c/d4d1561d17eb72908e4489c0900d96e0484fac20'
  - url: 'https://git.kernel.org/stable/c/24fa213dffa470166ec014f979f36c6ff44afb45'
  - url: 'https://git.kernel.org/stable/c/f11cf946c0a92c560a890d68e4775723353599e1'
tags:
  - cve.org
epss: 0.00197
epssPercentile: 0.09455
ingestedAt: '2026-11-03T16:49:26.500Z'
---

## Overview

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

net: mctp: Don't access ifa_index when missing

In mctp_dump_addrinfo, ifa_index can be used to filter interfaces, but
only when the struct ifaddrmsg is provided. Otherwise it will be
comparing to uninitialised memory - reproducible in the syzkaller case from
dhcpd, or busybox "ip addr show".

The kernel MCTP implementation has always filtered by ifa_index, so
existing userspace programs expecting to dump MCTP addresses must
already be passing a valid ifa_index value (either 0 or a real index).

BUG: KMSAN: uninit-value in mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128
 mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128
 rtnl_dump_all+0x3ec/0x5b0 net/core/rtnetlink.c:4380
 rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6824
 netlink_dump+0x97b/0x1690 net/netlink/af_netlink.c:2309

## Affected

- `Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d < 8ef7b3f0db69e2f4a80be351f6aee9a4c2332ef9`
- `Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d < d22efcd246a7688599eefcf8e5c7985a3854ef5d`
- `Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d < acab78ae12c7fefb4f3bfe22e00770a5faa42724`
- `Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d < d4d1561d17eb72908e4489c0900d96e0484fac20`
- `Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d < 24fa213dffa470166ec014f979f36c6ff44afb45`
- `Linux >= 583be982d93479ea3d85091b0fd0b01201ede87d < f11cf946c0a92c560a890d68e4775723353599e1`
- `Linux 5.15`

## Remediation

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