CVE-2024-39502 – This is a use-after-free vulnerability in the L... (How to Fix)

Q: What is the severity of CVE-2024-39502?

CVE-2024-39502 has a CVSS score of 7.8 (HIGH). This is a use-after-free vulnerability in the Linux kernel's ionic network driver where netif_napi_del() doesn't properly reset the .poll pointer, allowing napi_enable() to be called on already-freed memory. This affects systems using the ionic driver for network interfaces and can cause kernel panics.

📋 TL;DR

This is a use-after-free vulnerability in the Linux kernel's ionic network driver where netif_napi_del() doesn't properly reset the .poll pointer, allowing napi_enable() to be called on already-freed memory. This affects systems using the ionic driver for network interfaces and can cause kernel panics.

💻 Affected Systems

Products:

Linux kernel with ionic network 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 using the ionic network driver. The vulnerability is triggered by specific ethtool queue reconfiguration sequences.

📦 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 →

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 causing data loss or service disruption.

🟠

Likely Case

System crash or kernel panic when network queue configuration is changed via ethtool commands, resulting in temporary denial of service.

🟢

If Mitigated

No impact if the vulnerability is patched or the ionic driver is not in use.

🌐 Internet-Facing: MEDIUM - Systems with network interfaces using the ionic driver could be crashed remotely if attackers can trigger queue reconfiguration.

🏢 Internal Only: MEDIUM - Internal systems using the ionic driver could be crashed by local users or through network configuration changes.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to execute ethtool commands with specific parameters. Local access or remote access with appropriate privileges needed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 0d19267cb150e8f76ade210e16ee820a77f684e7, 183ebc167a8a19e916b885d4bb61a3491991bfa5, 60cd714871cd5a683353a355cbb17a685245cf84, 79f18a41dd056115d685f3b0a419c7cd40055e13, 8edd18dab443863e9e48f084e7f123fca3065e4e

Vendor Advisory: https://git.kernel.org/stable/c/0d19267cb150e8f76ade210e16ee820a77f684e7

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. Check your distribution's security advisories for specific patched kernel versions. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable ionic driver

linux

Blacklist or disable the ionic network driver if not needed

echo 'blacklist ionic' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot

Restrict ethtool access

linux

Limit who can execute ethtool commands to prevent triggering the vulnerability

chmod 750 /sbin/ethtool
setcap cap_net_admin+ep /sbin/ethtool

🧯 If You Can't Patch

Avoid using ethtool to reconfigure network queues on systems with ionic driver
Implement strict access controls to prevent unauthorized users from running ethtool commands

🔍 How to Verify

Check if Vulnerable:

Check if ionic driver is loaded: lsmod | grep ionic. If loaded, check kernel version against patched versions.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes the fix commits or check with your distribution's security advisory. Test ethtool queue reconfiguration after patch.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages mentioning napi_enable or ionic driver
System crash logs with stack traces showing ionic_qcq_enable

Network Indicators:

Sudden network interface disappearance
Unexpected system reboots after network configuration changes

SIEM Query:

event_type:kernel_panic AND (message:*napi_enable* OR message:*ionic*)

📊 Metadata

CVE ID: CVE-2024-39502

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-416

Published: July 12, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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