Bug 2535367 (CVE-2026-90025)

Summary:	CVE-2026-90025 kernel: usb: typec: ucsi: displayport: Fix OOB altmode array index
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 USB Type-C DisplayPort (UCSI displayport) driver. An attacker with physical proximity or control over a connected USB-C device could provide a specially crafted response from the Port Partner Manager (PPM). This invalid response could cause an out-of-bounds array access, leading to a kernel crash and a denial of service (DoS) on the affected system.	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 2026-09-16 12:22:19 UTC

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

usb: typec: ucsi: displayport: Fix OOB altmode array index

The UCSI displayport driver indexes the connector's port altmode array
with the GET_CURRENT_CAM response after checking it is not 0xff. The
port altmode array is UCSI_MAX_ALTMODES elements long. If the PPM
returns an invalid GET_CURRENT_CAM response above UCSI_MAX_ALTMODES and
not equal to 0xff, the kernel may crash with an array index OOB error.

Update the UCSI displayport driver to verify the current cam is less
than UCSI_MAX_ALTMODES before accessing the port altmode array.

Comment 1 Keith Grant 2026-09-22 14:03:14 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90025.mbox