Bug 2540521 (CVE-2026-97435)

Summary:	CVE-2026-97435 kernel: net: dsa: sja1105: flower: reject cross-chip redirect
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 sja1105 network switch driver. When configuring traffic control redirect actions, the driver does not verify whether the destination port belongs to the local switch device. A local privileged user could exploit this flaw by configuring a cross-chip redirect, causing the driver to program an invalid port index into the hardware. This issue can lead to packets being routed to an incorrect port or an out-of-bounds access that results in a Denial of Service (DoS).	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 2026-09-24 17:06:34 UTC

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

net: dsa: sja1105: flower: reject cross-chip redirect

dsa_port_from_netdev() may return a valid port from a different switch
chip. Programming another chip's port index into the local hardware
causes redirection to the wrong port, or an out-of-bounds access if the
index exceeds the local chip's port count.

Apply a minimal fix that adds a check to catch this case and adjusts the
extack message. When cls->common.skip_sw is not set, the operation could
instead redirect to the upstream port and let the software or upstream
switch(es) handle the forward, but that is not addressed here.

Comment 1 Mauro Matteo Cascella 2026-09-29 13:40:33 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97435.mbox