Bug 2517068 (CVE-2026-74497)

Summary:	CVE-2026-74497 kernel: ALSA: usb-audio: Clamp frame size in implicit-feedback mode
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:	rhel-process-autobot, 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 (Advanced Linux Sound Architecture) USB audio subsystem. A connected USB device could send oversized synchronization packets, causing the system to process data beyond its hardware limits. This could lead to a denial of service (DoS) or system instability.	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 2026-08-15 12:47:58 UTC

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

ALSA: usb-audio: Clamp frame size in implicit-feedback mode

snd_usb_handle_sync_urb() scales received sync packet sizes by the sender's
stride and stores the result directly in out_packet->packet_size[i]. If a
connected USB device sends an oversized sync packet, this frame count can
exceed ep->maxframesize.

The un-clamped frame count then propagates to the playback endpoint queue,
potentially driving packet transfers beyond the endpoint's hardware frame
limits.

Cap the calculated frame count against ep->maxframesize in
snd_usb_handle_sync_urb() to prevent oversized packets from entering the
playback queue.

Comment 1 Mauro Matteo Cascella 2026-08-19 15:57:11 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081540-CVE-2026-74497-e00f@gregkh/T