Bug 2536651 (CVE-2026-93082)

Summary:	CVE-2026-93082 kernel: firmware: arm_scmi: Unwind P2A receiver mailbox setup failure
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
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 `arm_scmi` firmware. When the `mailbox_chan_setup()` function attempts to acquire an additional P2A receiver channel after successfully acquiring the primary channel, a failure in the subsequent request can leave the primary channel allocated. This resource management issue prevents the primary channel from being properly released, potentially leading to probe deferral or other system setup failures, which could result in a Denial of Service (DoS).	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 19:02:23 UTC

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

firmware: arm_scmi: Unwind P2A receiver mailbox setup failure

mailbox_chan_setup() can request an additional P2A receiver channel after
successfully acquiring the primary P2A channel. If that later request
fails, the function returns immediately and leaves the primary channel
allocated.

Unwind the primary mailbox channel before returning the error so probe
deferral or other setup failures do not leave the channel busy for later
probe attempts.

Comment 1 gkamathe 2026-09-19 23:37:14 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93082.mbox