---
id: CVE-2025-40279
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: sched: act_connmark: initialize struct tc_ife to fix kernel leak

  In tcf_connmark_dump(), the variable 'opt' was partially initialized using a
  designatied initiali…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: sched: act_connmark: initialize struct tc_ife to fix kernel leak

  In tcf_connmark_dump(), the variable 'opt' was partially initialized using a
  designatied initiali…
severity: none
published: '2025-12-06'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T19:10:00.173'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40279'
references:
  - url: 'https://git.kernel.org/stable/c/218b67c8c8246d47a2a7910eae80abe4861fe2b7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/25837889ec062f2b7618142cd80253dff3da5343'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/31e4aa93e2e5b5647fc235b0f6ee329646878f9e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/51cb05d4fd632596816ba44e882e84db9fb28a7e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/62b656e43eaeae445a39cd8021a4f47065af4389'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/73cc56c608c209d3d666cc571293b090a471da70'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00197
epssPercentile: 0.08733
ingestedAt: '2026-10-15T19:25:46.333Z'
---

## Overview

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

net: sched: act_connmark: initialize struct tc_ife to fix kernel leak

In tcf_connmark_dump(), the variable 'opt' was partially initialized using a
designatied initializer. While the padding bytes are reamined
uninitialized. nla_put() copies the entire structure into a
netlink message, these uninitialized bytes leaked to userspace.

Initialize the structure with memset before assigning its fields
to ensure all members and padding are cleared prior to beign copied.

## Remediation

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