---
id: CVE-2024-54683
title: 'netfilter: IDLETIMER: Fix for possible ABBA deadlock'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: IDLETIMER: Fix for possible ABBA deadlock

  Deletion of the last rule referencing a given idletimer may happen at
  the same time as a read of its file in sysfs…
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: adp
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c <
    5493d84a40f0e61da74e1b0db640845997836b4e
  - >-
    Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c <
    8c2c8445cda8f59c38dec7dc10509bcb23ae26a0
  - >-
    Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c <
    45fe76573a2557f632e248cc141342233f422b9a
  - >-
    Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c <
    f36b01994d68ffc253c8296e2228dfe6e6431c03
  - Linux 2.6.36
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2025-10-01T19:55:27.468543Z'
published: '2025-01-11'
updated: '2026-10-30'
sourceUpdated: '2026-10-30T12:20:16.039Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2024-54683'
references:
  - url: 'https://git.kernel.org/stable/c/5493d84a40f0e61da74e1b0db640845997836b4e'
  - url: 'https://git.kernel.org/stable/c/8c2c8445cda8f59c38dec7dc10509bcb23ae26a0'
  - url: 'https://git.kernel.org/stable/c/45fe76573a2557f632e248cc141342233f422b9a'
  - url: 'https://git.kernel.org/stable/c/f36b01994d68ffc253c8296e2228dfe6e6431c03'
tags:
  - cve.org
epss: 0.00162
epssPercentile: 0.05415
ingestedAt: '2026-11-03T14:47:02.521Z'
---

## Overview

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

netfilter: IDLETIMER: Fix for possible ABBA deadlock

Deletion of the last rule referencing a given idletimer may happen at
the same time as a read of its file in sysfs:

| ======================================================
| WARNING: possible circular locking dependency detected
| 6.12.0-rc7-01692-g5e9a28f41134-dirty #594 Not tainted
| ------------------------------------------------------
| iptables/3303 is trying to acquire lock:
| ffff8881057e04b8 (kn->active#48){++++}-{0:0}, at: __kernfs_remove+0x20
|
| but task is already holding lock:
| ffffffffa0249068 (list_mutex){+.+.}-{3:3}, at: idletimer_tg_destroy_v]
|
| which lock already depends on the new lock.

A simple reproducer is:

| #!/bin/bash
|
| while true; do
|         iptables -A INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
|         iptables -D INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
| done &
| while true; do
|         cat /sys/class/xt_idletimer/timers/testme >/dev/null
| done

Avoid this by freeing list_mutex right after deleting the element from
the list, then continuing with the teardown.

## Affected

- `Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c < 5493d84a40f0e61da74e1b0db640845997836b4e`
- `Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c < 8c2c8445cda8f59c38dec7dc10509bcb23ae26a0`
- `Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c < 45fe76573a2557f632e248cc141342233f422b9a`
- `Linux >= 0902b469bd25065aa0688c3cee6f11744c817e7c < f36b01994d68ffc253c8296e2228dfe6e6431c03`
- `Linux 2.6.36`

## Remediation

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