Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (lm90) Add lock protection to lm90_alert
Sashiko reports:
lm90_alert() executes in the smbus alert context and calls lm90_update_confreg() to disable the hardware alert line, without acquiring hwmon_lock.
Concurrently, sysfs write operations (such as lm90_write_convrate) hold the hwmon_lock, temporarily modify data->config, and then restore it.
If an alert interrupt occurs concurrently with a sysfs write, the sysfs path will overwrite the alert handler’s modifications to data->config and the hardware register.
This unintentionally re-enables the hardware alert line while the alarm is still active, causing an interrupt storm.
Add the missing lock to lm90_alert() to solve the problem.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 5.14.0 (+4 more)