CVE-2024-54683

/// Technical description

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 /sy

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References