Bug 2535234 (CVE-2026-90032)

Summary:	CVE-2026-90032 kernel: media: usbtv: keep device alive while ALSA card exists
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 `usbtv` media driver. A use-after-free vulnerability can occur when an open Pulse-Code Modulation (PCM) file outlives a USB device disconnect. A local attacker could exploit this by disconnecting a USB TV device while an ALSA PCM file is open, leading to a dereference of freed memory. This could result in system instability or a denial of service.	Story Points:	---
Clone Of:		Environment:
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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 2026-09-16 11:38:22 UTC

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

media: usbtv: keep device alive while ALSA card exists

The ALSA PCM callbacks store the driver state in pcm->private_data. An
open PCM file can outlive USB disconnect because usbtv_audio_free() uses
snd_card_free_when_closed(). The disconnect path can then drop the V4L2
device reference and free struct usbtv before ALSA releases the substream,
so a later close dereferences freed memory in snd_usbtv_pcm_close().

Take a V4L2 device reference for the ALSA card and drop it from the card
private_free callback. This keeps struct usbtv valid until ALSA has closed
the remaining files and freed the card.

Comment 1 Keith Grant 2026-09-16 23:33:49 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90032.mbox