CVE-2023-53834

What it actually does

NULL pointer dereference in the ina2xx I2C probe handler when the first compatible string in a device tree node lacks a matching entry in the driver's I2C device ID table, causing the id pointer to be NULL while the driver attempts to use it.

Why it matters to the business

Systems using certain power monitoring sensors defined in device trees may experience kernel crashes or boot failures, leading to unplanned downtime and potential loss of sensor data collection on affected Linux deployments.

How an attack unfolds

An attacker with the ability to influence or provide a crafted device tree (such as through a malicious kernel module load, compromised bootloader, or supply-chain device tree modification) can trigger the NULL dereference during driver initialization for unsupported compatible strings, resulting in a kernel panic.

How to fix it

Update the Linux kernel to a version containing commit a8e2ae6296d56478fb98ae7f739846ed121f154f which replaces the NULL id pointer usage with the already-populated type variable and adds a generic name entry to the ina2xx_config table.

How to confirm the fix worked

Confirm the presence of commit a8e2ae6296d56478fb98ae7f739846ed121f154f in the kernel source or binary; test probe with a device tree node containing multiple compatible strings where the first is absent from the driver table.

Typical attack path

1. Supply or modify device tree to list an unknown compatible string first followed by a supported one
2. Ensure the I2C device ID table lacks an entry for the first string
3. Trigger driver probe via device registration or module load
4. Observe NULL dereference and kernel panic

How to detect it

Review kernel logs for NULL pointer dereference oops messages referencing ina2xx_probe or of_i2c_get_board_info during device initialization; inspect loaded device trees for power-sensor nodes with multiple compatible strings.

What your security team should do

• Prioritize kernel updates containing the referenced commit on all systems exposing IIO ADC drivers
• Audit device trees for multi-compatible power sensor nodes using ti,ina2xx family strings
• Monitor kernel logs for ina2xx probe failures during boot or hotplug events