CVE-2026-98278
net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check
Description
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.
INFO
Published Date :
Oct. 6, 2026, 9:18 a.m.
Last Modified :
Oct. 6, 2026, 9:18 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the Linux kernel patch to remove WARN_ON_ONCE().
- Review and correct tunnel remote endpoint configurations.
- Ensure routes do not resolve back to the tunnel device.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-98278.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/150dba2c69e93302af24a0c868eebe4871e2e107 | |
| https://git.kernel.org/stable/c/d8eb177632dacda28bc6130c2105afbf5b791eb0 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-98278 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-98278
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-98278 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-98278 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 06, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98278.json">CVE-2026-98278</a> Added Reference https://git.kernel.org/stable/c/150dba2c69e93302af24a0c868eebe4871e2e107 Added Reference https://git.kernel.org/stable/c/d8eb177632dacda28bc6130c2105afbf5b791eb0