Описание
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify()
The acpi_power_meter driver's .notify() callback function,
acpi_power_meter_notify(), calls hwmon_device_unregister() under a lock
that is also acquired by callbacks in sysfs attributes of the device
being unregistered which is prone to deadlocks between sysfs access and
device removal.
Address this by moving the hwmon device removal in
acpi_power_meter_notify() outside the lock in question, but notice
that doing it alone is not sufficient because two concurrent
METER_NOTIFY_CONFIG notifications may be attempting to remove the
same device at the same time. To prevent that from happening, add a
new lock serializing the execution of the switch () statement in
acpi_power_meter_notify(). For simplicity, it is a static mutex
which should not be a problem from the performance perspective.
The new lock also allows the hwmon_device_register_with_info()
in acpi_power_meter_notify() to be called outside the inner lock
because it prevents the other notifications handled by that function
from manipulating the "resource" object while the hwmon device based
on it is being registered. The sending of ACPI netlink messages from
acpi_power_meter_notify() is serialized by the new lock too which
generally helps to ensure that the order of handling firmware
notifications is the same as the order of sending netlink messages
related to them.
In addition, notice that hwmon_device_register_with_info() may fail
in which case resource->hwmon_dev will become an error pointer,
so add checks to avoid attempting to unregister the hwmon device
pointer to by it in that case to acpi_power_meter_notify() and
acpi_power_meter_remove().
A deadlock vulnerability was found in the ACPI power meter hwmon driver. The acpi_power_meter_notify() function holds a lock while calling hwmon_device_unregister(), but sysfs attribute callbacks also acquire this lock, creating a circular dependency that can cause system hangs.
Отчет
This affects systems with ACPI power meter hardware that receive configuration change notifications from firmware. Triggering the deadlock requires specific firmware events concurrent with sysfs access, which limits practical exploitability to denial of service.
Меры по смягчению последствий
To mitigate this issue, prevent the acpi_power_meter module from being loaded. See https://access.redhat.com/solutions/41278 for instructions on how to blacklist a kernel module to prevent it from loading automatically.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| 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
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify() The acpi_power_meter driver's .notify() callback function, acpi_power_meter_notify(), calls hwmon_device_unregister() under a lock that is also acquired by callbacks in sysfs attributes of the device being unregistered which is prone to deadlocks between sysfs access and device removal. Address this by moving the hwmon device removal in acpi_power_meter_notify() outside the lock in question, but notice that doing it alone is not sufficient because two concurrent METER_NOTIFY_CONFIG notifications may be attempting to remove the same device at the same time. To prevent that from happening, add a new lock serializing the execution of the switch () statement in acpi_power_meter_notify(). For simplicity, it is a static mutex which should not be a problem from the performance perspective. The new lock also allows the hwmon_device_register_with_...
In the Linux kernel, the following vulnerability has been resolved: hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify() The acpi_power_meter driver's .notify() callback function, acpi_power_meter_notify(), calls hwmon_device_unregister() under a lock that is also acquired by callbacks in sysfs attributes of the device being unregistered which is prone to deadlocks between sysfs access and device removal. Address this by moving the hwmon device removal in acpi_power_meter_notify() outside the lock in question, but notice that doing it alone is not sufficient because two concurrent METER_NOTIFY_CONFIG notifications may be attempting to remove the same device at the same time. To prevent that from happening, add a new lock serializing the execution of the switch () statement in acpi_power_meter_notify(). For simplicity, it is a static mutex which should not be a problem from the performance perspective. The new lock also allows the hwmon_device_register_with
In the Linux kernel, the following vulnerability has been resolved: h ...
In the Linux kernel, the following vulnerability has been resolved: hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify() The acpi_power_meter driver's .notify() callback function, acpi_power_meter_notify(), calls hwmon_device_unregister() under a lock that is also acquired by callbacks in sysfs attributes of the device being unregistered which is prone to deadlocks between sysfs access and device removal. Address this by moving the hwmon device removal in acpi_power_meter_notify() outside the lock in question, but notice that doing it alone is not sufficient because two concurrent METER_NOTIFY_CONFIG notifications may be attempting to remove the same device at the same time. To prevent that from happening, add a new lock serializing the execution of the switch () statement in acpi_power_meter_notify(). For simplicity, it is a static mutex which should not be a problem from the performance perspective. The new lock also allows the hwmon_device_register_w...
EPSS
5.5 Medium
CVSS3