CVE-2024-39492

What it actually does

The flaw triggers an unnecessary kernel warning in cmdq_mbox_shutdown when pm_runtime_get_sync returns 1 for an already-active runtime PM state instead of checking only for negative error returns.

Why it matters to the business

Produces log noise during device shutdown on affected MediaTek platforms, increasing alert fatigue for operators and complicating log analysis without affecting system functionality or availability.

How an attack unfolds

No exploitation path exists because the issue is a non-security warning condition in the shutdown path of the mailbox driver; threat actor references in input data do not apply to this kernel fix.

How to fix it

Update to a kernel containing commit 1e4e1f7bbec459b5cd9d31d9fa6c9e06e9339940 or later equivalent that changes the WARN_ON condition to check only for return value less than zero.

How to confirm the fix worked

Confirm the fix by inspecting the cmdq_mbox_shutdown function for the corrected WARN_ON condition on pm_runtime_get_sync return value and verify absence of the warning during controlled shutdown tests on MediaTek CMDQ hardware.

How to detect it

Review kernel logs for pm_runtime_get_sync warnings originating from cmdq_mbox_shutdown during shutdown sequences; no ransomware or known actor IOCs apply given the non-exploitable nature and false KEV status.

What your security team should do

• Apply the referenced kernel commit or distribution update containing the pm_runtime_get_sync check fix
• Monitor kernel logs for the specific pm_runtime warning during shutdown on affected devices until patched
• Prioritize updates on Android and embedded MediaTek deployments given the listed threat actor context