CVE-2024-38631

What it actually does

Out-of-bounds array index access in the PAC1934 IIO ADC driver when handling average current and voltage measurements through sysfs interfaces, as the driver supports only four physical channels but exposes additional virtual channels.

Why it matters to the business

Potential kernel crashes or memory corruption on Linux systems using the PAC1934 ADC chip, leading to system instability or denial of service in affected environments.

How an attack unfolds

An attacker with local access to a system using the PAC1934 device can interact with sysfs attributes for average measurements, triggering the out-of-bounds access in the kernel driver.

How to fix it

Update the Linux kernel to version 6.9.4 or apply the patch from commit 8dbcb3a8cfdf8ff5afce62dad50790278ff0d3b7.

How to confirm the fix worked

Verify kernel version is at least 6.9.4 and check that the PAC1934 driver no longer allows access to invalid array indices for average channels.

Typical attack path

1. Gain local access to affected Linux system
2. Locate sysfs entries for PAC1934 average measurements
3. Read or write to attributes exposing average current/voltage
4. Trigger kernel memory corruption

How to detect it

Look for kernel logs indicating out-of-bounds access or crashes in the iio adc pac1934 module; monitor sysfs accesses to average channels on systems with the device.

What your security team should do

• Prioritize kernel updates on systems with PAC1934 hardware
• Monitor for kernel oops or panics related to iio:adc:PAC1934
• Restrict sysfs access where possible