CVE-2023-53105
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's mlx5e network driver. When unloading the mlx5_core module while traffic control (tc) flows are still active, the system attempts to access an already-destroyed lock, causing a kernel panic. This affects systems using Mellanox network adapters with the mlx5 driver and tc offloading features.
💻 Affected Systems
- Linux kernel with mlx5e 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially requiring physical intervention to reboot the system.
Likely Case
System crash during driver module unload or system shutdown when tc flows are active, causing temporary service disruption.
If Mitigated
No impact if the vulnerable code path is not triggered (no tc flows active during module unload).
🎯 Exploit Status
Exploitation requires local access and specific timing conditions during driver module operations. This is a reliability issue rather than a security bypass vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 01fdaea410787fe372daeaeda93a29ed0606d334, b7350f8dbe0c2a1d4d3ad7c35b610abd3cb91750, or c9668f0b1d28570327dbba189f2c61f6f9e43ae7
Vendor Advisory: https://git.kernel.org/stable/c/01fdaea410787fe372daeaeda93a29ed0606d334
Restart Required: Yes
Instructions:
1. Update Linux kernel to a version containing the fix commits. 2. Reboot the system to load the new kernel. 3. Verify the mlx5_core module loads without issues.
🔧 Temporary Workarounds
Avoid driver unload during active tc flows
linuxEnsure all tc flows are removed before unloading the mlx5_core module
# Remove all tc flows before module unload
tc qdisc del dev <interface> root
# Then unload module
modprobe -r mlx5_core
🧯 If You Can't Patch
- Avoid unloading the mlx5_core module while the system is in production use
- Implement monitoring to detect and alert on kernel panic events related to mlx5 driver operations
🔍 How to Verify
Check if Vulnerable:
Check if your kernel version is before the fix commits and if mlx5_core module is loaded with tc offloading featuresCheck Version:
uname -rVerify Fix Applied:
Check kernel version includes the fix commits and test unloading mlx5_core module with active tc flows📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages containing 'mlx5_core' and 'mutex_lock'
- NULL pointer dereference errors in kernel logs with mlx5e stack traces
Network Indicators:
- Sudden loss of network connectivity on interfaces using mlx5 driver
SIEM Query:
kernel_panic AND (mlx5_core OR mlx5e)