Bug 2536298 (CVE-2026-93080)

Summary:	CVE-2026-93080 kernel: firmware: arm_scmi: Fix transport device teardown lookup
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 ARM System Control and Management Interface (SCMI) firmware. This vulnerability occurs because the `scmi_device_destroy()` function, responsible for tearing down SCMI transport devices, uses an incorrect lookup mechanism. Malformed firmware with duplicate protocol child nodes could exploit this to reuse an existing transport device and then prematurely destroy it. This could lead to system instability or a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-17 17:16:55 UTC

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

firmware: arm_scmi: Fix transport device teardown lookup

SCMI transport devices are deliberately excluded from normal SCMI bus
matching so protocol drivers cannot bind to the internal transport
children. However, scmi_device_destroy() uses the same protocol/name
lookup to find devices that must be unregistered during channel teardown.

Split the match helper so driver matching still skips transport devices,
while explicit child lookup can find them for teardown. Use a shared
transport-device name prefix macro for both matching and name generation.

Since transport-device names are derived from direction and protocol ID,
reject duplicate protocol channel setup before creating or finding a
transport device. This prevents malformed firmware with duplicate
protocol child nodes from reusing an existing transport device and then
destroying it when the duplicate IDR insertion fails.

Comment 1 gkamathe 2026-09-19 23:26:07 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93080.mbox