---
id: CVE-2023-53189
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv6/addrconf: fix a potential refcount underflow for idev

  Now in addrconf_mod_rs_timer(), reference idev depends on whether
  rs_timer is not pending
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv6/addrconf: fix a potential refcount underflow for idev

  Now in addrconf_mod_rs_timer(), reference idev depends on whether
  rs_timer is not pending. Then modify rs_ti…
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-191
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.10.105, < 4.14.322'
  - 'linux_kernel >= 4.15, < 4.19.291'
  - 'linux_kernel >= 4.20, < 5.4.251'
  - 'linux_kernel >= 5.5, < 5.10.188'
  - 'linux_kernel >= 5.11, < 5.15.121'
  - 'linux_kernel >= 5.16, < 6.1.40'
  - 'linux_kernel >= 6.2, < 6.4.5'
  - linux_kernel = 6.5
patched:
  - linux_kernel 6.4.5
published: '2025-09-15'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:17:39.233'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-53189'
references:
  - url: 'https://git.kernel.org/stable/c/06a0716949c22e2aefb648526580671197151acc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1f656e483eb4733d62f18dfb206a49b78f60f495'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2ad31ce40e8182860b631e37209e93e543790b7c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/436b7cc7eae7851c184b671ed7a4a64c750b86f7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/82abd1c37d3bf2a2658b34772c17a25a6f9cca42'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c6395e32935d35e6f935e7caf1c2dac5a95943b4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c7eeba47058532f6077d6a658e38b6698f6ae71a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/df62fdcd004afa72ecbed0e862ebb983acd3aa57'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00168
epssPercentile: 0.06121
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:34:23.338472Z'
ingestedAt: '2026-10-15T22:48:25.401Z'
---

## Overview

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

ipv6/addrconf: fix a potential refcount underflow for idev

Now in addrconf_mod_rs_timer(), reference idev depends on whether
rs_timer is not pending. Then modify rs_timer timeout.

There is a time gap in [1], during which if the pending rs_timer
becomes not pending. It will miss to hold idev, but the rs_timer
is activated. Thus rs_timer callback function addrconf_rs_timer()
will be executed and put idev later without holding idev. A refcount
underflow issue for idev can be caused by this.

	if (!timer_pending(&idev->rs_timer))
		in6_dev_hold(idev);
		  <--------------[1]
	mod_timer(&idev->rs_timer, jiffies + when);

To fix the issue, hold idev if mod_timer() return 0.

## Affected

- `linux_kernel >= 3.10.105, < 4.14.322`
- `linux_kernel >= 4.15, < 4.19.291`
- `linux_kernel >= 4.20, < 5.4.251`
- `linux_kernel >= 5.5, < 5.10.188`
- `linux_kernel >= 5.11, < 5.15.121`
- `linux_kernel >= 5.16, < 6.1.40`
- `linux_kernel >= 6.2, < 6.4.5`
- `linux_kernel = 6.5`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.4.5`