---
id: CVE-2026-98278
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check

  ipip_fill_forward_path() and ip6_tnl_fill_forward_path() look up the
  route to the tunnel's remot…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check

  ipip_fill_forward_path() and ip6_tnl_fill_forward_path() look up the
  route to the tunnel's remot…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ab427db17885814069bae891834f20842f0ac3a4 <
    d8eb177632dacda28bc6130c2105afbf5b791eb0
  - >-
    Linux >= ab427db17885814069bae891834f20842f0ac3a4 <
    150dba2c69e93302af24a0c868eebe4871e2e107
  - Linux 6.19
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T09:18:17.660'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98278'
references:
  - url: 'https://git.kernel.org/stable/c/150dba2c69e93302af24a0c868eebe4871e2e107'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d8eb177632dacda28bc6130c2105afbf5b791eb0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-06T08:50:17.422Z'
---

## Overview

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

net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check

ipip_fill_forward_path() and ip6_tnl_fill_forward_path() look up the
route to the tunnel's remote endpoint and set ctx->dev to its device,
which is the tunnel itself when that route resolves back to the tunnel.
dev_fill_forward_path() then makes no progress and trips
WARN_ON_ONCE(last_dev == ctx->dev) as soon as a flowtable tries to
offload a flow through the tunnel. That routing loop is a configuration
any CAP_NET_ADMIN user can set up, and ip_tunnel_xmit() and
ip6_tnl_xmit() already treat it as a tx error, so remove the warning and
just fail the walk, as commit 008e7a7c293b ("net: remove WARN_ON_ONCE
when accessing forward path array") did for the path stack overflow.

## Remediation

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