Bug 2546483 (CVE-2026-98266)

Summary:	CVE-2026-98266 kernel: ALSA: core: Fix potential UAF after asynchronous card release
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 Advanced Linux Sound Architecture (ALSA) subsystem. When an audio card is released asynchronously, such as during the disconnection of a USB sound device, active background tasks may continue accessing the device structure after it has been deallocated due to missing reference counting. A local user could exploit this use-after-free vulnerability to cause a system crash, leading to a Denial of Service (DoS), or potentially execute arbitrary code.	Story Points:	---
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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 2026-10-06 09:29:08 UTC

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

ALSA: core: Fix potential UAF after asynchronous card release

Usually a sound driver releases the resources assigned to the card via
snd_card_free(), and it synchronizes with the whole release procedure.
However, when the card is released asynchronously via
snd_card_free_when_closed() like USB-audio driver, the situation is
slightly different; although the snd_card_disconnect() call at the
disconnection guarantees that any newer accesses will be gated, the
in-flight tasks might be still accessing to the underlying card->dev
device even after the disconnection, which would cause a
use-after-free in the end, as reported by fuzzers.

For addressing the bug above, this patch takes the refcount of
card->dev at initialization of the card object, and releases at its
destructor.   This assures the availability of the card->dev in its
whole lifecycle.

Comment 1 gkamathe 2026-10-10 19:54:30 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98266.mbox