Bug 2507210 (CVE-2026-64478)

Summary:	CVE-2026-64478 kernel: ALSA: usb-audio: avoid kobject path lookup in DualSense match
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:	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 USB audio driver, specifically affecting DualSense controllers. A local attacker with physical access to a DualSense controller could exploit this by rapidly disconnecting and reconnecting the device due to a weak physical connection. This action can cause the kernel to attempt to access an invalid memory location, leading to a system crash and 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 2026-07-25 10:10:50 UTC

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

ALSA: usb-audio: avoid kobject path lookup in DualSense match

The DualSense jack-detection input handler verifies that a matching input
device belongs to the same physical controller by building kobject path
strings for both the input device and the USB audio device, then comparing
the path prefix.

This was observed when a weak physical connection caused the controller
to rapidly disconnect and reconnect. During that repeated hotplug,
snd_dualsense_ih_match() can run while the controller's USB device is
being disconnected. kobject_get_path() walks ancestor kobjects and
dereferences their names; if the USB device kobject name is no longer
valid, this can fault in strlen():

  RIP: 0010:strlen+0x10/0x30
  Call Trace:
   kobject_get_path+0x34/0x150
   snd_dualsense_ih_match+0x49/0xd0 [snd_usb_audio]
   input_register_device+0x566/0x6a0
   ps_probe+0xb89/0x1590 [hid_playstation]

The same ownership check can be done without building kobject path
strings. The input device is parented below the HID device, USB interface
and USB device, so walking the input device parent chain and comparing
against the mixer USB device preserves the check without dereferencing
kobject names during disconnect.

Comment 1 TEJ RATHI 2026-07-29 11:16:13 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072547-CVE-2026-64478-2795@gregkh/T