Bug 2461471 (CVE-2026-31581)

Summary:	CVE-2026-31581 kernel: ALSA: 6fire: fix use-after-free on disconnect
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 6fire USB audio device driver. During the disconnection process of a 6fire USB audio device, a use-after-free vulnerability occurs. This happens when the system attempts to write to memory that has already been deallocated, which can lead to memory corruption and potentially cause system instability or 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 2026-04-24 15:03:22 UTC

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

ALSA: 6fire: fix use-after-free on disconnect

In usb6fire_chip_abort(), the chip struct is allocated as the card's
private data (via snd_card_new with sizeof(struct sfire_chip)).  When
snd_card_free_when_closed() is called and no file handles are open, the
card and embedded chip are freed synchronously.  The subsequent
chip->card = NULL write then hits freed slab memory.

Call trace:
  usb6fire_chip_abort sound/usb/6fire/chip.c:59 [inline]
  usb6fire_chip_disconnect+0x348/0x358 sound/usb/6fire/chip.c:182
  usb_unbind_interface+0x1a8/0x88c drivers/usb/core/driver.c:458
  ...
  hub_event+0x1a04/0x4518 drivers/usb/core/hub.c:5953

Fix by moving the card lifecycle out of usb6fire_chip_abort() and into
usb6fire_chip_disconnect().  The card pointer is saved in a local
before any teardown, snd_card_disconnect() is called first to prevent
new opens, URBs are aborted while chip is still valid, and
snd_card_free_when_closed() is called last so chip is never accessed
after the card may be freed.

Comment 1 Keith Grant 2026-04-24 18:28:08 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042411-CVE-2026-31581-9bc2@gregkh/T

Comment 3 errata-xmlrpc 2026-06-10 20:00:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:25120 https://access.redhat.com/errata/RHSA-2026:25120

Comment 4 errata-xmlrpc 2026-06-10 21:39:01 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:25121 https://access.redhat.com/errata/RHSA-2026:25121

Comment 5 errata-xmlrpc 2026-06-11 06:49:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:25191 https://access.redhat.com/errata/RHSA-2026:25191

Comment 6 errata-xmlrpc 2026-06-11 10:13:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:25217 https://access.redhat.com/errata/RHSA-2026:25217