CVE-2024-39492
📋 TL;DR
This CVE addresses a false positive warning in the Linux kernel's MediaTek Command Queue mailbox driver during shutdown. The vulnerability doesn't allow attackers to execute arbitrary code or gain unauthorized access, but causes unnecessary warning messages when the power management runtime state is active. It affects Linux systems using MediaTek hardware with the mtk-cmdq mailbox driver.
💻 Affected Systems
- Linux kernel with MediaTek Command Queue mailbox driver (mtk-cmdq)
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
System instability or denial of service due to excessive warning messages flooding logs, potentially masking other legitimate issues.
Likely Case
Benign warning messages in kernel logs during system shutdown, causing confusion for administrators but no security compromise.
If Mitigated
No security impact - just cleaner log output during shutdown procedures.
🎯 Exploit Status
This is not a security vulnerability that can be exploited for privilege escalation or code execution. It's a false positive warning fix.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commit 2d42a37a4518478f075ccf848242b4a50e313a46 or 747a69a119c469121385543f21c2d08562968ccc
Vendor Advisory: https://git.kernel.org/stable/c/2d42a37a4518478f075ccf848242b4a50e313a46
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commit. 2. Reboot system to load new kernel. 3. For embedded MediaTek devices, obtain updated firmware from manufacturer.
🔧 Temporary Workarounds
Suppress kernel warnings
linuxConfigure kernel to suppress warning messages from this specific driver
echo 'module.mtk_cmdq = 0' > /sys/module/mtk_cmdq/parameters/debug_level
🧯 If You Can't Patch
- Monitor kernel logs for excessive warning messages during shutdown
- Ignore benign warnings from mtk-cmdq driver as they don't indicate security issues
🔍 How to Verify
Check if Vulnerable:
Check kernel logs during shutdown for 'WARN_ON' messages related to mtk-cmdq or pm_runtime_get_syncCheck Version:
uname -rVerify Fix Applied:
After patching, verify no WARN_ON messages appear in dmesg during shutdown related to cmdq_mbox_shutdown📡 Detection & Monitoring
Log Indicators:
- WARN_ON messages in kernel logs during shutdown mentioning cmdq_mbox_shutdown or pm_runtime_get_sync
Network Indicators:
- None - this is a local driver issue
SIEM Query:
source="kernel" AND "WARN_ON" AND ("cmdq" OR "pm_runtime_get_sync")