CVE-2025-39769
📋 TL;DR
This CVE describes a lockdep warning in the Linux kernel's bnxt_en driver that occurs during module removal (rmmod). The vulnerability doesn't allow remote exploitation but causes a kernel warning that could potentially lead to system instability or crashes during driver removal. Only systems using the Broadcom NetXtreme-E (bnxt_en) network driver are affected.
💻 Affected Systems
- Linux kernel with bnxt_en driver
📦 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 →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 →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
Kernel panic or system crash during driver removal/module unloading, potentially requiring physical access to reboot the system.
Likely Case
Kernel warning message in system logs during driver removal, with possible minor system instability but no remote exploitation.
If Mitigated
No impact beyond warning messages in logs if proper kernel locking is maintained.
🎯 Exploit Status
Exploitation requires local privileged access (root) to trigger driver removal. Not a remote code execution vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commit 5885d39dce879fbbc953f40e19adb60c29802302
Vendor Advisory: https://git.kernel.org/stable/c/5885d39dce879fbbc953f40e19adb60c29802302
Restart Required: No
Instructions:
1. Update Linux kernel to version containing the fix commit 2. Rebuild kernel if compiling from source 3. No system restart required for driver fix, but kernel update may require reboot
🔧 Temporary Workarounds
Avoid driver removal
allDo not remove bnxt_en driver module while system is running
# Avoid running: rmmod bnxt_en
# Avoid running: modprobe -r bnxt_en
🧯 If You Can't Patch
- Avoid removing or reloading the bnxt_en driver module
- Monitor system logs for lockdep warnings and have recovery procedures ready
🔍 How to Verify
Check if Vulnerable:
Check if system has bnxt_en driver loaded and kernel version is within affected rangeCheck Version:
uname -rVerify Fix Applied:
Check kernel version includes fix commit 5885d39dce879fbbc953f40e19adb60c29802302📡 Detection & Monitoring
Log Indicators:
- WARNING messages in kernel logs about bnxt_free_ntp_fltrs
- lockdep warnings during driver removal
Network Indicators:
- None - this is a local driver issue
SIEM Query:
kernel:WARNING AND bnxt_free_ntp_fltrs OR lockdep