Описание
In the Linux kernel, the following vulnerability has been resolved: usbnet: Prevents free active kevent The root cause of this issue are:
- When probing the usbnet device, executing usbnet_link_change(dev, 0, 0); put the kevent work in global workqueue. However, the kevent has not yet been scheduled when the usbnet device is unregistered. Therefore, executing free_netdev() results in the "free active object (kevent)" error reported here.
- Another factor is that when calling usbnet_disconnect()->unregister_netdev(),
if the usbnet device is up, ndo_stop() is executed to cancel the kevent.
However, because the device is not up, ndo_stop() is not executed.
The solution to this problem is to cancel the kevent before executing
free_netdev().
A use-after-free vulnerability was found in the Linux kernel's usbnet driver. When a usbnet device is unregistered before a scheduled kevent work item executes, free_netdev() frees memory that the pending kevent will later access. This occurs because kevent cancellation is missing before device cleanup when the device was never brought up.
Отчет
This race window exists during USB network device probe/disconnect sequences. The timing requirements make exploitation difficult but the underlying UAF could potentially be leveraged for code execution.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Under investigation | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | 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: usbnet: Prevents free active kevent The root cause of this issue are: 1. When probing the usbnet device, executing usbnet_link_change(dev, 0, 0); put the kevent work in global workqueue. However, the kevent has not yet been scheduled when the usbnet device is unregistered. Therefore, executing free_netdev() results in the "free active object (kevent)" error reported here. 2. Another factor is that when calling usbnet_disconnect()->unregister_netdev(), if the usbnet device is up, ndo_stop() is executed to cancel the kevent. However, because the device is not up, ndo_stop() is not executed. The solution to this problem is to cancel the kevent before executing free_netdev().
In the Linux kernel, the following vulnerability has been resolved: usbnet: Prevents free active kevent The root cause of this issue are: 1. When probing the usbnet device, executing usbnet_link_change(dev, 0, 0); put the kevent work in global workqueue. However, the kevent has not yet been scheduled when the usbnet device is unregistered. Therefore, executing free_netdev() results in the "free active object (kevent)" error reported here. 2. Another factor is that when calling usbnet_disconnect()->unregister_netdev(), if the usbnet device is up, ndo_stop() is executed to cancel the kevent. However, because the device is not up, ndo_stop() is not executed. The solution to this problem is to cancel the kevent before executing free_netdev().
In the Linux kernel, the following vulnerability has been resolved: u ...
In the Linux kernel, the following vulnerability has been resolved: usbnet: Prevents free active kevent The root cause of this issue are: 1. When probing the usbnet device, executing usbnet_link_change(dev, 0, 0); put the kevent work in global workqueue. However, the kevent has not yet been scheduled when the usbnet device is unregistered. Therefore, executing free_netdev() results in the "free active object (kevent)" error reported here. 2. Another factor is that when calling usbnet_disconnect()->unregister_netdev(), if the usbnet device is up, ndo_stop() is executed to cancel the kevent. However, because the device is not up, ndo_stop() is not executed. The solution to this problem is to cancel the kevent before executing free_netdev().
ELSA-2026-50100: Unbreakable Enterprise kernel security update (IMPORTANT)
EPSS
4.7 Medium
CVSS3