Bug 2555188 (CVE-2026-98758)

Summary:	CVE-2026-98758 kernel: usb: typec: ucsi: glink: fix use-after-free of ucsi on remove
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:	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) GLINK driver. A local attacker with administrative privileges could trigger this flaw during device removal, leading to a Denial of Service (DoS) or potentially arbitrary code execution. The issue occurs because background callback tasks can continue to queue and run after the driver has unregistered its resources, causing the system to access memory that has already been freed.	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 2026-10-18 15:59:47 UTC

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

usb: typec: ucsi: glink: fix use-after-free of ucsi on remove

The pmic_glink client is released by the devres cleanup, which runs
after pmic_glink_ucsi_remove() has returned, so its notification
callbacks can queue work until then. Work that runs after
ucsi_unregister() has been called touches freed state: it dereferences
the connector array that ucsi_unregister() freed, or registers and
unregisters the instance a second time.

Disable both work items with disable_work_sync() before unregistering,
and unregister only if the instance is still registered.

This issue was found by an in-house static analysis tool.

Comment 1 Mauro Matteo Cascella 2026-10-23 04:07:22 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98758.mbox