CVE-2024-39506 – This CVE describes a NULL pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2024-39506?

CVE-2024-39506 has a CVSS score of 5.5 (MEDIUM). This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's liquidio network driver. The flaw occurs in the lio_vf_rep_copy_packet() function where a page pointer is checked for NULL but then unconditionally passed to skb_add_rx_frag(), potentially causing kernel crashes or denial of service. Systems using affected liquidio drivers are vulnerable.

📋 TL;DR

This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's liquidio network driver. The flaw occurs in the lio_vf_rep_copy_packet() function where a page pointer is checked for NULL but then unconditionally passed to skb_add_rx_frag(), potentially causing kernel crashes or denial of service. Systems using affected liquidio drivers are vulnerable.

💻 Affected Systems

Products:

Linux kernel with liquidio driver

Versions: Linux kernel versions before the fix commits (specific versions vary by distribution)

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with liquidio network hardware (Cavium/OCTEON-based NICs). Most standard Linux installations are not vulnerable.

📦 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...

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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 →

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 access to restore functionality.

🟠

Likely Case

System instability, kernel crashes, or denial of service affecting network functionality on systems with liquidio hardware.

🟢

If Mitigated

Minor performance impact or no effect if the vulnerable code path isn't triggered.

🌐 Internet-Facing: LOW - Requires specific liquidio hardware and network conditions to trigger.

🏢 Internal Only: MEDIUM - Internal systems with liquidio hardware could experience crashes affecting business operations.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Exploitation requires specific hardware (liquidio NICs) and network conditions to trigger the vulnerable code path. No public exploits are known.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 87d6bdc006f0cbf297a3b2ad6e40ede4c3ee5dc2, a6f4d0ec170a46b5f453cacf55dff5989b42bbfa, a86490a3712cc513113440a606a0e77130abd47c, c44711b78608c98a3e6b49ce91678cd0917d5349, cbf18d8128a753cb632bef39470d19befd9c7347

Vendor Advisory: https://git.kernel.org/stable/c/87d6bdc006f0cbf297a3b2ad6e40ede4c3ee5dc2

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable liquidio module

linux

Prevent loading of vulnerable liquidio driver if not needed

echo 'blacklist liquidio' >> /etc/modprobe.d/blacklist.conf
rmmod liquidio

🧯 If You Can't Patch

Remove or disable liquidio network hardware if not essential
Implement network segmentation to isolate systems with liquidio hardware

🔍 How to Verify

Check if Vulnerable:

Check if liquidio module is loaded: lsmod | grep liquidio AND check kernel version against patched versions

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits and liquidio module loads without errors

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
System crash/reboot logs
liquidio driver error messages in dmesg

Network Indicators:

Sudden loss of network connectivity on liquidio interfaces

SIEM Query:

Search for kernel panic events or system crashes on hosts with liquidio hardware

📊 Metadata

CVE ID: CVE-2024-39506

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: July 12, 2024

Last Updated: November 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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