Описание
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb: 6fire: Avoid embedded URBs
The USB 6fire driver uses URBs embedded in different structs for PCM,
MIDI and communication, and this is basically a buggy implementation
nowadays; since a URB is managed with a refcount, this may lead to a
UAF when the URB is released asynchronously.
For addressing the problem, this patch converts those embedded URBs to
ones that are properly allocated via usb_alloc_urb(). The
pcm_urb.packets[] is gone, as it's allocated by usb_alloc_urb(), hence
it's found in urb.iso_frame_desc[] instead.
The conversions are rather straightforward; each embedded struct urb
is changed to a pointer, and its callers are updated accordingly.
The resource for those structs are released in the common destructor
functions (usb6fire_comm_free(), etc), which are called at both the
init error path and the disconnect.
No functional changes, only compile-tested.
A flaw was found in the Linux kernel's ALSA USB 6fire audio driver. The driver improperly embeds USB Request Blocks (URBs)—structures that manage USB communications—directly inside driver objects rather than allocating them dynamically. Because URBs rely on reference counting and can be released asynchronously, this design can cause memory to be accessed after it has been freed. A local attacker could exploit this flaw to cause a Denial of Service (DoS) via a system crash or potentially execute arbitrary code.
Отчет
The ALSA USB 6fire driver embeds reference counted URBs inside PCM, MIDI, and communication runtime objects. An URB can remain referenced or be released asynchronously after the containing runtime object has been destroyed, resulting in a kernel use after free and possible memory corruption. A local process may help trigger the vulnerable lifetime transition by using the affected audio or USB device while disconnect, cleanup, or an error path races with URB completion. For the CVSS the PR:L value is used because practical software triggering requires a local user or process with access to the affected ALSA or USB device. The issue is not network reachable and requires the USB 6fire driver and compatible hardware to be present. Impact is at least a local denial of service via kernel crash and in the worst case may include confidentiality and integrity impact or privilege escalation because the underlying primitive is a kernel use after free. The asynchronous lifetime window makes exploitation complex and configuration dependent.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Fix deferred |
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Дополнительная информация
Статус:
EPSS
4.7 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb: 6fire: Avoid embedded URBs The USB 6fire driver uses URBs embedded in different structs for PCM, MIDI and communication, and this is basically a buggy implementation nowadays; since a URB is managed with a refcount, this may lead to a UAF when the URB is released asynchronously. For addressing the problem, this patch converts those embedded URBs to ones that are properly allocated via usb_alloc_urb(). The pcm_urb.packets[] is gone, as it's allocated by usb_alloc_urb(), hence it's found in urb.iso_frame_desc[] instead. The conversions are rather straightforward; each embedded struct urb is changed to a pointer, and its callers are updated accordingly. The resource for those structs are released in the common destructor functions (usb6fire_comm_free(), etc), which are called at both the init error path and the disconnect. No functional changes, only compile-tested.
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb: 6fire: Avoid embedded URBs The USB 6fire driver uses URBs embedded in different structs for PCM, MIDI and communication, and this is basically a buggy implementation nowadays; since a URB is managed with a refcount, this may lead to a UAF when the URB is released asynchronously. For addressing the problem, this patch converts those embedded URBs to ones that are properly allocated via usb_alloc_urb(). The pcm_urb.packets[] is gone, as it's allocated by usb_alloc_urb(), hence it's found in urb.iso_frame_desc[] instead. The conversions are rather straightforward; each embedded struct urb is changed to a pointer, and its callers are updated accordingly. The resource for those structs are released in the common destructor functions (usb6fire_comm_free(), etc), which are called at both the init error path and the disconnect. No functional changes, only compile-tested.
In the Linux kernel, the following vulnerability has been resolved: A ...
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb: 6fire: Avoid embedded URBs The USB 6fire driver uses URBs embedded in different structs for PCM, MIDI and communication, and this is basically a buggy implementation nowadays; since a URB is managed with a refcount, this may lead to a UAF when the URB is released asynchronously. For addressing the problem, this patch converts those embedded URBs to ones that are properly allocated via usb_alloc_urb(). The pcm_urb.packets[] is gone, as it's allocated by usb_alloc_urb(), hence it's found in urb.iso_frame_desc[] instead. The conversions are rather straightforward; each embedded struct urb is changed to a pointer, and its callers are updated accordingly. The resource for those structs are released in the common destructor functions (usb6fire_comm_free(), etc), which are called at both the init error path and the disconnect. No functional changes, only compile-tested.
ELSA-2026-500572: Unbreakable Enterprise kernel security update (IMPORTANT)
EPSS
4.7 Medium
CVSS3