---
id: CVE-2026-89740
title: 'serial: imx: serialize imx_uart_ports[] lifetime'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  serial: imx: serialize imx_uart_ports[] lifetime

  imx_uart_probe() publishes its devm-allocated port in imx_uart_ports[]
  before uart_add_one_port() because console setu…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-825
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 <
    abc17fd508a511669997e48f8b014d8aa043abdf
  - >-
    Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 <
    681696ae9e4a28bdf54893c807dfe4a6c08e30a5
  - >-
    Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 <
    28b932202fcdbeb2ef58d89ce4363f480433c234
  - >-
    Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 <
    7429dce56a73bc080a8c072edb167106f73a08ae
  - >-
    Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 <
    8b0b29fdcb47907ae0296b8fe829e918e05e300f
  - Linux 2.6.27
published: '2026-09-11'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:48:33.586Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89740'
references:
  - url: 'https://git.kernel.org/stable/c/abc17fd508a511669997e48f8b014d8aa043abdf'
  - url: 'https://git.kernel.org/stable/c/681696ae9e4a28bdf54893c807dfe4a6c08e30a5'
  - url: 'https://git.kernel.org/stable/c/28b932202fcdbeb2ef58d89ce4363f480433c234'
  - url: 'https://git.kernel.org/stable/c/7429dce56a73bc080a8c072edb167106f73a08ae'
  - url: 'https://git.kernel.org/stable/c/8b0b29fdcb47907ae0296b8fe829e918e05e300f'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89740.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89740'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532424'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89740'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89740'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89740.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00206
epssPercentile: 0.10586
ingestedAt: '2026-09-14T11:11:19.884Z'
---

## Overview

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

serial: imx: serialize imx_uart_ports[] lifetime

imx_uart_probe() publishes its devm-allocated port in imx_uart_ports[]
before uart_add_one_port() because console setup uses the table. The entry
is not cleared when adding the port fails or after removal, leaving a
dangling pointer.

A sibling probe can register the shared console through that stale entry.
This was reproduced under KASAN on QEMU mcimx6ul-evk by unbinding a
sibling UART, unbinding the console UART and rebinding the sibling.

Keep the entry valid through uart_remove_one_port(), then clear it. Protect
port addition and removal together with their table updates so sibling
operations cannot interleave. Reject an occupied slot rather than
clobbering an active port during a duplicate-line probe.

## Affected

- `Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 < abc17fd508a511669997e48f8b014d8aa043abdf`
- `Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 < 681696ae9e4a28bdf54893c807dfe4a6c08e30a5`
- `Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 < 28b932202fcdbeb2ef58d89ce4363f480433c234`
- `Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 < 7429dce56a73bc080a8c072edb167106f73a08ae`
- `Linux >= dbff4e9ea2e83fda89143389bfb229cb29425a32 < 8b0b29fdcb47907ae0296b8fe829e918e05e300f`
- `Linux 2.6.27`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89740.json)