Описание
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (hp-wmi-sensors) Fix use-after-free in fungible_show()
nsensor->current_state is dynamically replaced as the sensor's state
changes. update_numeric_sensor_from_wobj() does this by freeing the
old string and installing a new one:
if (strcmp(trimmed, nsensor->current_state)) {
new_string = hp_wmi_strdup(dev, trimmed);
if (new_string) {
devm_kfree(dev, nsensor->current_state);
nsensor->current_state = new_string;
}
}
This function is only ever called from hp_wmi_update_info() while
state->lock is held, so the free-and-replace itself is properly
serialized against concurrent updates.
fungible_show(), however, reads the same pointer after the lock has
already been dropped:
err = hp_wmi_update_info(state, info);
if (err)
return err;
switch (prop) {
...
case HP_WMI_PROPERTY_CURRENT_STATE:
seq_printf(seqf, "%s\n", nsensor->current_state);
break;
hp_wmi_update_info() takes state->lock internally and releases it
before returning, so by the time fungible_show() dereferences
nsensor->current_state in seq_printf(), no lock is held. Two
processes reading a sensor's current_state debugfs entry at
overlapping times (or one reading it while another read of the same
sensor triggers a refresh) can race: one thread's seq_printf() can
be part-way through printing the string at the moment another
thread's call into update_numeric_sensor_from_wobj() frees it with
devm_kfree() and installs a new pointer, causing a use-after-free
read.
Take state->lock around the read in fungible_show() as well, so it
can never run concurrently with the free-and-replace in
update_numeric_sensor_from_wobj().
A flaw was found in the Linux kernel's HP WMI Sensors (hp-wmi-sensors) driver. Due to a missing lock when reading sensor properties, a race condition can occur when sensor data is freed and replaced during an update while another operation is reading it. A local user could exploit this flaw by concurrently accessing sensor files, triggering a use-after-free read that may cause a Denial of Service (DoS) or disclose sensitive kernel memory.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| 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 | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected |
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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: (hp-wmi-sensors) Fix use-after-free in fungible_show() nsensor->current_state is dynamically replaced as the sensor's state changes. update_numeric_sensor_from_wobj() does this by freeing the old string and installing a new one: if (strcmp(trimmed, nsensor->current_state)) { new_string = hp_wmi_strdup(dev, trimmed); if (new_string) { devm_kfree(dev, nsensor->current_state); nsensor->current_state = new_string; } } This function is only ever called from hp_wmi_update_info() while state->lock is held, so the free-and-replace itself is properly serialized against concurrent updates. fungible_show(), however, reads the same pointer after the lock has already been dropped: err = hp_wmi_update_info(state, info); if (err) return err; switch (prop) { ... case HP_WMI_PROPERTY_CURRENT_STATE: seq_printf(seqf, "%s\n", nsensor->current_state); break; hp_wmi_update_info() takes state->lock internally and releases it before...
In the Linux kernel, the following vulnerability has been resolved: hwmon: (hp-wmi-sensors) Fix use-after-free in fungible_show() nsensor->current_state is dynamically replaced as the sensor's state changes. update_numeric_sensor_from_wobj() does this by freeing the old string and installing a new one: if (strcmp(trimmed, nsensor->current_state)) { new_string = hp_wmi_strdup(dev, trimmed); if (new_string) { devm_kfree(dev, nsensor->current_state); nsensor->current_state = new_string; } } This function is only ever called from hp_wmi_update_info() while state->lock is held, so the free-and-replace itself is properly serialized against concurrent updates. fungible_show(), however, reads the same pointer after the lock has already been dropped: err = hp_wmi_update_info(state, info); if (err) return err; switch (prop) { ... case HP_WMI_PROPERTY_CURRENT_STATE: seq_printf(seqf, "%s\n", nsensor->current_state); break; hp_wmi_update_info() takes state->lock int
hwmon: (hp-wmi-sensors) Fix use-after-free in fungible_show()
In the Linux kernel, the following vulnerability has been resolved: h ...
In the Linux kernel, the following vulnerability has been resolved: hwmon: (hp-wmi-sensors) Fix use-after-free in fungible_show() nsensor->current_state is dynamically replaced as the sensor's state changes. update_numeric_sensor_from_wobj() does this by freeing the old string and installing a new one: if (strcmp(trimmed, nsensor->current_state)) { new_string = hp_wmi_strdup(dev, trimmed); if (new_string) { devm_kfree(dev, nsensor->current_state); nsensor->current_state = new_string; } } This function is only ever called from hp_wmi_update_info() while state->lock is held, so the free-and-replace itself is properly serialized against concurrent updates. fungible_show(), however, reads the same pointer after the lock has already been dropped: err = hp_wmi_update_info(state, info); if (err) return err; switch (prop) { ... case HP_WMI_PROPERTY_CURRENT_STATE: seq_printf(seqf, "%s\n", nsensor->current_state); break; hp_wmi_update_info() takes state->lock ...
EPSS
5.5 Medium
CVSS3