CVE-2025-38142

What it actually does

Unchecked negative return value from find_ec_sensor_index() passed to get_sensor_info() in asus-ec-sensors hwmon driver enables invalid memory access and undefined behavior.

Why it matters to the business

Systems using affected ASUS embedded controller sensor drivers may experience kernel instability or crashes, increasing downtime risk on servers and devices with high ecosystem prevalence of Linux kernel deployments.

How an attack unfolds

An attacker with local access triggers read_string() on a non-existent sensor index; the missing bounds check allows the negative value to propagate, potentially causing memory corruption or denial of service. No public exploits or ransomware use observed despite listed threat actor mentions of related kernel issues.

How to fix it

Update Linux kernel to commit 6bf529ce84dccc0074dbc704e70aee4aa545057e or later; for affected container images update secrets-store-csi-driver and related packages to 1.5.1-r1 or newer.

How to confirm the fix worked

Confirm kernel source contains the added negative index check returning -EINVAL; test by attempting read_string() calls with invalid sensor indices and verify graceful error returns instead of undefined behavior.

Typical attack path

1. Obtain local execution context on target Linux system
2. Interact with hwmon sysfs interface to invoke read_string() on asus-ec-sensors
3. Supply or trigger lookup for a sensor index that does not exist
4. Trigger undefined behavior via unchecked negative index in get_sensor_info()

How to detect it

Review kernel logs for oops or panic entries involving asus-ec-sensors or find_ec_sensor_index; inspect sysfs accesses to hwmon devices for unusual sensor index patterns.

What your security team should do

• Prioritize kernel upgrades on all systems exposing hwmon interfaces within 30 days given publication age
• Audit deployed Linux images for presence of asus-ec-sensors driver
• Monitor EPSS trend and threat actor activity around related kernel privilege issues