---
id: CVE-2023-52924
title: 'netfilter: nf_tables: don''t skip expired elements during walk'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: nf_tables: don't skip expired elements during walk

  There is an asymmetry between commit/abort and preparation phase if the
  following conditions are met:

  1.…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 <
    94313a196b44184b5b52c1876da6a537701b425a
  - >-
    Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 <
    1da4874d05da1526b11b82fc7f3c7ac38749ddf8
  - >-
    Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 <
    b15ea4017af82011dd55225ce77cce3d4dfc169c
  - >-
    Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 <
    7c7e658a36f8b1522bd3586d8137e5f93a25ddc5
  - >-
    Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 <
    59dab3bf0b8fc08eb802721c0532f13dd89209b8
  - >-
    Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 <
    bd156ce9553dcaf2d6ee2c825d1a5a1718e86524
  - >-
    Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 <
    24138933b97b055d486e8064b4a1721702442a9b
  - Linux 4.1
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:13:51.204735Z'
published: '2025-02-05'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:20:52.702Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-52924'
references:
  - url: 'https://git.kernel.org/stable/c/94313a196b44184b5b52c1876da6a537701b425a'
  - url: 'https://git.kernel.org/stable/c/1da4874d05da1526b11b82fc7f3c7ac38749ddf8'
  - url: 'https://git.kernel.org/stable/c/b15ea4017af82011dd55225ce77cce3d4dfc169c'
  - url: 'https://git.kernel.org/stable/c/7c7e658a36f8b1522bd3586d8137e5f93a25ddc5'
  - url: 'https://git.kernel.org/stable/c/59dab3bf0b8fc08eb802721c0532f13dd89209b8'
  - url: 'https://git.kernel.org/stable/c/bd156ce9553dcaf2d6ee2c825d1a5a1718e86524'
  - url: 'https://git.kernel.org/stable/c/24138933b97b055d486e8064b4a1721702442a9b'
tags:
  - cve.org
epss: 0.00215
epssPercentile: 0.1192
ingestedAt: '2026-11-05T22:38:31.750Z'
---

## Overview

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

netfilter: nf_tables: don't skip expired elements during walk

There is an asymmetry between commit/abort and preparation phase if the
following conditions are met:

1. set is a verdict map ("1.2.3.4 : jump foo")
2. timeouts are enabled

In this case, following sequence is problematic:

1. element E in set S refers to chain C
2. userspace requests removal of set S
3. kernel does a set walk to decrement chain->use count for all elements
   from preparation phase
4. kernel does another set walk to remove elements from the commit phase
   (or another walk to do a chain->use increment for all elements from
    abort phase)

If E has already expired in 1), it will be ignored during list walk, so its use count
won't have been changed.

Then, when set is culled, ->destroy callback will zap the element via
nf_tables_set_elem_destroy(), but this function is only safe for
elements that have been deactivated earlier from the preparation phase:
lack of earlier deactivate removes the element but leaks the chain use
count, which results in a WARN splat when the chain gets removed later,
plus a leak of the nft_chain structure.

Update pipapo_get() not to skip expired elements, otherwise flush
command reports bogus ENOENT errors.

## Affected

- `Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 < 94313a196b44184b5b52c1876da6a537701b425a`
- `Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 < 1da4874d05da1526b11b82fc7f3c7ac38749ddf8`
- `Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 < b15ea4017af82011dd55225ce77cce3d4dfc169c`
- `Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 < 7c7e658a36f8b1522bd3586d8137e5f93a25ddc5`
- `Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 < 59dab3bf0b8fc08eb802721c0532f13dd89209b8`
- `Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 < bd156ce9553dcaf2d6ee2c825d1a5a1718e86524`
- `Linux >= 9d0982927e79049675cb6c6c04a0ebb3dad5a434 < 24138933b97b055d486e8064b4a1721702442a9b`
- `Linux 4.1`

## Remediation

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