---
id: CVE-2026-43035
title: >-
  net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to
  prevent an info-leak
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to
  prevent an info-leak


  When building netlink messages, tc_chain_fill_node() never initializ…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    903c3405cfcc7700260e456ab66a5867586c9e69
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    71a3eda7e850ae844cb8993065f4e410c11a46ce
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    4ae5d23f51fb91d7d1140c6f1ba77ab0756054c3
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    e35f5195cd44ff4053fbc5d71ea97681728a0099
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    d6db08484c6cb3d4ad696246f9d288eceba2a078
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    906997ea3766c24fbbf9cc4bf17c047315bbd138
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    1091b3c174441a52fdbb92e2fe00338f9371a91c
  - >-
    Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e <
    e6e3eb5ee89ac4c163d46429391c889a1bb5e404
  - Linux 4.19
published: '2026-05-01'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:48:38.121Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43035'
references:
  - url: 'https://git.kernel.org/stable/c/903c3405cfcc7700260e456ab66a5867586c9e69'
  - url: 'https://git.kernel.org/stable/c/71a3eda7e850ae844cb8993065f4e410c11a46ce'
  - url: 'https://git.kernel.org/stable/c/4ae5d23f51fb91d7d1140c6f1ba77ab0756054c3'
  - url: 'https://git.kernel.org/stable/c/e35f5195cd44ff4053fbc5d71ea97681728a0099'
  - url: 'https://git.kernel.org/stable/c/d6db08484c6cb3d4ad696246f9d288eceba2a078'
  - url: 'https://git.kernel.org/stable/c/906997ea3766c24fbbf9cc4bf17c047315bbd138'
  - url: 'https://git.kernel.org/stable/c/1091b3c174441a52fdbb92e2fe00338f9371a91c'
  - url: 'https://git.kernel.org/stable/c/e6e3eb5ee89ac4c163d46429391c889a1bb5e404'
tags:
  - cve.org
epss: 0.00129
epssPercentile: 0.02877
ingestedAt: '2026-09-08T15:33:26.989Z'
---

## Overview

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

net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak

When building netlink messages, tc_chain_fill_node() never initializes
the tcm_info field of struct tcmsg. Since the allocation is not zeroed,
kernel heap memory is leaked to userspace through this 4-byte field.

The fix simply zeroes tcm_info alongside the other fields that are
already initialized.

## Affected

- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < 903c3405cfcc7700260e456ab66a5867586c9e69`
- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < 71a3eda7e850ae844cb8993065f4e410c11a46ce`
- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < 4ae5d23f51fb91d7d1140c6f1ba77ab0756054c3`
- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < e35f5195cd44ff4053fbc5d71ea97681728a0099`
- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < d6db08484c6cb3d4ad696246f9d288eceba2a078`
- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < 906997ea3766c24fbbf9cc4bf17c047315bbd138`
- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < 1091b3c174441a52fdbb92e2fe00338f9371a91c`
- `Linux >= 32a4f5ecd7381f30ae3bb36dea77a150ba68af2e < e6e3eb5ee89ac4c163d46429391c889a1bb5e404`
- `Linux 4.19`

## Remediation

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