CVE-2024-26963

What it actually does

The dwc3-am62 driver fails to acquire a runtime PM reference before register operations during module removal when the device is already suspended, and omits of_platform_depopulate in .remove after of_platform_populate in .probe, resulting in a clk_core_disable warning and broken reload behavior.

Why it matters to the business

Systems using affected Linux kernels on AM62 platforms may experience driver unload/reload failures, leading to reduced availability during module updates or hotplug events and requiring reboots to restore USB functionality.

How an attack unfolds

An attacker with local access triggers repeated module removal and reload sequences to induce the clock disable warning and leave the USB controller in an inconsistent state, though no remote code execution path exists.

How to fix it

Update the Linux kernel to a version containing commit 6c6a45645a2e6a272dfde14eddbb6706de63c25d or later; rebuild and deploy the updated kernel image on all affected AM62-based systems.

How to confirm the fix worked

Confirm the running kernel contains commit 6c6a45645a2e6a272dfde14eddbb6706de63c25d, then perform module unload/reload cycles while monitoring for absence of the clk_core_disable warning.

Typical attack path

1. Obtain local shell or module manipulation privileges
2. Unload the dwc3-am62 module while runtime suspended
3. Trigger the clk warning and observe reload failure
4. Abuse resulting USB instability for denial of service

How to detect it

Search kernel logs for the exact clk_core_disable warning string during module removal events; inspect dmesg or journalctl output around USB driver unload timestamps.

• clk:162:3 already disabled
• WARNING: CPU:.*PID:.*at drivers/clk/clk.c:1090 clk_core_disable

What your security team should do

• Prioritize kernel upgrade on all AM62 devices within standard patch windows
• Add kernel version checks to configuration management and image build pipelines
• Monitor for future similar runtime PM and platform device cleanup issues in USB drivers