Bug 2541420 (CVE-2026-100079)

Summary:	CVE-2026-100079 kernel: usb: typec: ucsi: unregister debugfs entries on teardown
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
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 USB Type-C Connector System Software Interface (UCSI) driver. This vulnerability can result in a Denial of Service (DoS) or system instability due to improper resource cleanup during device teardown. Debug filesystem (debugfs) entries created during registration are not removed when unregistering the interface, remaining active until the instance is destroyed. When a driver unregisters and re-registers the same interface across subsystem restarts, the kernel attempts to recreate existing entries, which can cause driver operational failures.	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 2026-09-25 13:26:31 UTC

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

usb: typec: ucsi: unregister debugfs entries on teardown

ucsi_register() creates per-instance debugfs entries, but
ucsi_unregister() keeps them around until ucsi_destroy().

Drivers like ucsi_glink that unregister/register the same UCSI
instance across remoteproc restart then try to create an already
existing debugfs directory and log:

  debugfs: 'pmic_glink.ucsi.0' already exists in 'ucsi'

Unregister debugfs entries as part of ucsi_unregister(), and
clear ucsi->debugfs after freeing it so repeated unregister
paths remain safe.

Comment 1 Mauro Matteo Cascella 2026-09-30 15:21:25 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-100079.mbox