CVE-2024-56660 – A NULL pointer dereference vulnerability in the... (How to Fix)

Q: What is the severity of CVE-2024-56660?

CVE-2024-56660 has a CVSS score of 5.5 (MEDIUM). A NULL pointer dereference vulnerability in the Linux kernel's mlx5 driver could cause kernel crashes or denial of service. This affects systems using Mellanox network adapters with the mlx5 driver enabled. Attackers with local access could potentially trigger this vulnerability.

📋 TL;DR

A NULL pointer dereference vulnerability in the Linux kernel's mlx5 driver could cause kernel crashes or denial of service. This affects systems using Mellanox network adapters with the mlx5 driver enabled. Attackers with local access could potentially trigger this vulnerability.

💻 Affected Systems

Products:

Linux kernel with mlx5 driver

Versions: Linux kernel versions before fixes in stable releases (check specific kernel versions from references)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with Mellanox network adapters using the mlx5 driver module.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, requiring physical or remote console access to reboot.

🟠

Likely Case

System instability or crash requiring reboot, potentially causing service disruption.

🟢

If Mitigated

Limited impact due to local access requirement and kernel crash protections.

🌐 Internet-Facing: LOW - Requires local access to exploit, not directly reachable from internet.

🏢 Internal Only: MEDIUM - Local attackers or malicious users could cause denial of service on affected systems.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and knowledge of triggering conditions. No public exploit code identified.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel versions with commits 11776cff0b563c8b8a4fa76cab620bfb633a8cb8 and related fixes

Vendor Advisory: https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version. 2. Rebuild kernel if using custom kernel. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable mlx5 driver

linux

Remove or blacklist the mlx5 driver module if Mellanox networking is not required

echo 'blacklist mlx5_core' >> /etc/modprobe.d/blacklist-mlx5.conf
rmmod mlx5_core

🧯 If You Can't Patch

Restrict local access to affected systems
Implement kernel crash monitoring and automated recovery

🔍 How to Verify

Check if Vulnerable:

Check if mlx5_core module is loaded: lsmod | grep mlx5_core

Check Version:

uname -r

Verify Fix Applied:

Check kernel version: uname -r and verify it includes the fix commits

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/messages or dmesg
System crash/reboot events

Network Indicators:

Sudden loss of network connectivity on affected interfaces

SIEM Query:

EventID=41 OR (Source="kernel" AND Message="BUG: unable to handle kernel NULL pointer dereference")

📊 Metadata

CVE ID: CVE-2024-56660

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-476

Published: December 27, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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