CVE-2024-50232

What it actually does

A missing input validation check allows a zero value for the output data rate parameter in ad7124_write_raw to reach DIV_ROUND_CLOSEST inside ad7124_set_channel_odr, resulting in a kernel division-by-zero fault.

Why it matters to the business

Local users on systems that load the ad7124 IIO driver can trigger an immediate kernel crash, producing denial of service and potential loss of ongoing data acquisition workloads.

How an attack unfolds

An attacker with local access calls iio_write_channel_attribute (via iio_write_channel_raw) supplying a zero val; the call chain reaches ad7124_set_channel_odr without sanitization and executes the unchecked division, crashing the kernel.

How to fix it

Upgrade the Linux kernel to a release containing the upstream fix that adds a non-zero guard before the DIV_ROUND_CLOSEST call in ad7124_set_channel_odr.

How to confirm the fix worked

Confirm the running kernel contains the patch that rejects or sanitizes a zero val parameter in ad7124_write_raw; re-test the IIO write path with a zero value and verify it returns an error instead of crashing.

Typical attack path

1. Obtain local shell on affected Linux system
2. Invoke iio_write_channel_raw or equivalent sysfs write with val=0 on an ad7124 channel
3. Trigger ad7124_write_raw → ad7124_set_channel_odr path
4. Execute DIV_ROUND_CLOSEST with zero divisor
5. Kernel oops/panic occurs

How to detect it

Search kernel logs for oops/panic messages containing ad7124_set_channel_odr or division by zero originating from the IIO ADC subsystem; correlate with recent local user activity on IIO character devices or sysfs entries.

• ad7124_set_channel_odr
• division by zero
• iio_write_channel_raw

What your security team should do

• Prioritize kernel updates on any host exposing the ad7124 driver
• Restrict local user access to IIO sysfs interfaces where possible
• Add monitoring for division-by-zero kernel faults referencing ad7124