Bug 2507180 (CVE-2026-64410)

Summary:	CVE-2026-64410 kernel: netfilter: flowtable: IPIP tunnel hardware offload is not yet support
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's netfilter component, specifically concerning the handling of IPIP (IP-in-IP) tunnel hardware offload. The system attempts to utilize hardware offload for IPIP tunnels, a feature not yet supported by existing drivers. A remote attacker could potentially exploit this unsupported operation, leading to a denial of service, compromise of data integrity, or disclosure of sensitive information due to the improper processing of network traffic.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-25 10:09:14 UTC

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

netfilter: flowtable: IPIP tunnel hardware offload is not yet support

No driver supports for IPIP tunnels yet, give up early on setting up the
hardware offload for this scenario.

This patch adds a stub that can be enhanced to add more configuration
that are currently not supported. As of now, the offload work is
enqueued to the worker, then ignored if the hardware offload
configuration is not supported.

Check the NF_FLOW_HW flag to know if this entry was already tried once
to be offloaded so this is not retried on refresh when unsupported. Move
NF_FLOW_HW flag check to nf_flow_offload_add(). If this NF_FLOW_HW flag
is unset the _del and _stats variants are never called.

This can be updated later on to skip hardware offload work to be queued
in case hardware offload does not support it.

Comment 1 TEJ RATHI 2026-07-29 13:12:11 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072532-CVE-2026-64410-056f@gregkh/T