Bug 2532257 (CVE-2026-80965)

Summary:	CVE-2026-80965 kernel: ALSA: serial-u16550: Check card index validity at probe
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 ALSA serial-u16550 driver. This vulnerability occurs because the driver does not properly validate the card index when a device is manually bound via the sysfs interface. A local user could exploit this by providing an invalid card index, leading to an out-of-bounds memory access. This could result in a system crash, causing a denial of service.	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 2026-09-11 21:45:39 UTC

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

ALSA: serial-u16550: Check card index validity at probe

serial-u16550 driver blindly trusts that the given devptr->id value is
within the proper card index range at probe.  It's OK for the devices
the driver itself creates at the module probe time, but if the device
is bound manually via sysfs interface, this could be -1 as "none", and
this leads to OOB access for index[] and other parameters.

Add a sanity check for the card index and warn/correct it if it's a
value out of the range.

Comment 1 Keith Grant 2026-09-14 17:07:41 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80965.mbox