Bug 2536468 (CVE-2026-90208)

Summary:	CVE-2026-90208 kernel: clocksource/drivers/samsung_pwm: Switch to raw_spinlock_t type
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 `samsung_pwm` clock source driver. When the `PREEMPT_RT` (Preemptible Real-Time) feature is enabled on ARM systems, a regular spinlock is incorrectly converted to a sleeping lock. This can lead to a deadlock or system instability, resulting in a Denial of Service (DoS) for affected systems.	Story Points:	---
Clone Of:		Environment:
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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 2026-09-17 18:04:42 UTC

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

clocksource/drivers/samsung_pwm: Switch to raw_spinlock_t type

Samsung PWM timer might be used as a clock source on some legacy systems.
When PREEMPT_RT is enabled on ARM, regular spinlock is converted to a
sleeping lock (mutex-based), which must not be used in atomic context
such as hard interrupt handlers. Switch the samsung_pwm_lock to the
raw_spinlock, which remains a true non-sleeping spinlock even
under PREEMPT_RT.

Comment 1 Mauro Matteo Cascella 2026-09-24 11:40:15 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90208.mbox