CVE-2025-39832
📋 TL;DR
This CVE describes a lockdep assertion warning in the Linux kernel's mlx5 network driver when handling sync reset unload events during devlink reload operations. The vulnerability could cause kernel warnings and potential system instability for systems using Mellanox network adapters with the affected driver. Only Linux systems with specific mlx5 driver configurations are affected.
💻 Affected Systems
- Linux kernel mlx5 network 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 →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
System crash or kernel panic due to lock contention issues during network driver reset operations, leading to denial of service.
Likely Case
Kernel warning messages in system logs and potential temporary network disruption during driver reset operations.
If Mitigated
Minor performance impact or warning messages that don't affect system stability.
🎯 Exploit Status
Exploitation requires privileged access to trigger devlink reload operations and specific hardware/driver configuration.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing the fix commits: 06d897148e79638651800d851a69547b56b4be2e, 0c87dba9ccd3801d3b503f0b4fd41be343af4f06, 902a8bc23a24882200f57cadc270e15a2cfaf2bb, ddac9d0fe2493dd550cbfc75eeaf31e9b6dac959
Vendor Advisory: https://git.kernel.org/stable/c/06d897148e79638651800d851a69547b56b4be2e
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Reboot system to load new kernel. 3. Verify mlx5 driver version after reboot.
🔧 Temporary Workarounds
Avoid devlink reload operations
allPrevent triggering the vulnerable code path by avoiding devlink reload fw_activate operations on affected systems.
🧯 If You Can't Patch
- Avoid using devlink reload fw_activate functionality on systems with Mellanox network adapters
- Monitor system logs for lockdep warnings and be prepared for potential network disruption during maintenance
🔍 How to Verify
Check if Vulnerable:
Check kernel logs for lockdep warnings related to mlx5 driver during devlink reload operations. Examine kernel version and mlx5 driver code for vulnerable patterns.Check Version:
uname -r && modinfo mlx5_core | grep versionVerify Fix Applied:
After patching, verify the fix by checking that the specific git commit hashes are present in your kernel source. Test devlink reload operations and monitor for lockdep warnings.📡 Detection & Monitoring
Log Indicators:
- WARNING: CPU: ... at devl_assert_locked+
- mlx5_sync_reset_unload_event in call traces
- lockdep warnings mentioning mlx5 driver
Network Indicators:
- Temporary network disruption during driver reset operations
SIEM Query:
kernel_logs WARNING AND (devl_assert_locked OR mlx5_sync_reset)