---
id: CVE-2026-99070
title: 'ipv6: do not warn on route notification size race'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv6: do not warn on route notification size race

  fib6_info_hw_flags_set() sizes the skb with rt6_nlmsg_size() and later
  fills it with rt6_fill_node().  With nexthop c…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df <
    8a3b935b6b6037eefb36bd27a60793a008358e8d
  - >-
    Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df <
    7b112bd43f1172fb152e848570a957467008a5ae
  - >-
    Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df <
    4ac7d92a4698e34e614c254359665b9de1f65283
  - >-
    Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df <
    291fe0bafee78c95f9f2e7f579f17793fd5a1e5a
  - >-
    Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df <
    c97426ec649d99596d8969e1a052c16b14b7b485
  - Linux 5.12
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T12:23:13.342Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-99070'
references:
  - url: 'https://git.kernel.org/stable/c/8a3b935b6b6037eefb36bd27a60793a008358e8d'
  - url: 'https://git.kernel.org/stable/c/7b112bd43f1172fb152e848570a957467008a5ae'
  - url: 'https://git.kernel.org/stable/c/4ac7d92a4698e34e614c254359665b9de1f65283'
  - url: 'https://git.kernel.org/stable/c/291fe0bafee78c95f9f2e7f579f17793fd5a1e5a'
  - url: 'https://git.kernel.org/stable/c/c97426ec649d99596d8969e1a052c16b14b7b485'
tags:
  - cve.org
ingestedAt: '2026-10-23T13:24:55.516Z'
---

## Overview

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

ipv6: do not warn on route notification size race

fib6_info_hw_flags_set() sizes the skb with rt6_nlmsg_size() and later
fills it with rt6_fill_node().  With nexthop compatibility mode enabled,
a concurrent replacement can grow the group between these independent
snapshots.  rt6_fill_node() can then legitimately return -EMSGSIZE, so
the warning does not prove a sizing bug.

Remove the warning.  The existing error path still frees the skb and
reports the error to listeners.

## Affected

- `Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df < 8a3b935b6b6037eefb36bd27a60793a008358e8d`
- `Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df < 7b112bd43f1172fb152e848570a957467008a5ae`
- `Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df < 4ac7d92a4698e34e614c254359665b9de1f65283`
- `Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df < 291fe0bafee78c95f9f2e7f579f17793fd5a1e5a`
- `Linux >= 907eea486888cfe118c19759bbc4b8fca2e004df < c97426ec649d99596d8969e1a052c16b14b7b485`
- `Linux 5.12`

## Remediation

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