Bug 2555168 (CVE-2026-98669)

Summary:	CVE-2026-98669 kernel: iio: buffer: serialize buffer teardown with mode claims
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 Industrial I/O (IIO) subsystem. During device unregistration, the kernel disables and deactivates device buffers without acquiring the required lock to synchronize teardown with active buffer-mode claims. A local user could exploit this race condition to cause a Denial of Service (DoS) through a kernel crash caused by an invalid buffer state.	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 15:58:15 UTC

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

iio: buffer: serialize buffer teardown with mode claims

Buffer-mode claims hold mlock to guarantee that the device remains in
buffer mode until the claim is released. Normal buffer updates take
info_exist_lock followed by mlock in iio_update_buffers().

However, iio_device_unregister() disables and deactivates all buffers
without taking mlock. This can invalidate buffer state, including
active_scan_mask, while a buffer-mode claim is held.

Take mlock in iio_disable_all_buffers() so that unregister honors the
mode-claim lifetime guarantee. The info_exist_lock -> mlock ordering
matches iio_update_buffers().

Comment 1 Mauro Matteo Cascella 2026-10-21 23:22:44 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98669.mbox