CVE-2024-46784 – A race condition in the Linux kernel's Microsof... (How to Fix)

Q: What is the severity of CVE-2024-46784?

CVE-2024-46784 has a CVSS score of 5.5 (MEDIUM). A race condition in the Linux kernel's Microsoft Azure Network Adapter (MANA) driver causes kernel panic when network queue cleanup occurs before NAPI is properly initialized. This affects Linux systems using the MANA driver for Azure networking, potentially causing system crashes and denial of service.

📋 TL;DR

A race condition in the Linux kernel's Microsoft Azure Network Adapter (MANA) driver causes kernel panic when network queue cleanup occurs before NAPI is properly initialized. This affects Linux systems using the MANA driver for Azure networking, potentially causing system crashes and denial of service.

💻 Affected Systems

Products:

Linux kernel with MANA driver

Versions: Linux kernel versions with vulnerable MANA driver code (specific commit ranges in references)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using Microsoft Azure Network Adapter (MANA) driver, typically Azure virtual machines or systems with MANA hardware.

📦 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

System crash leading to denial of service, requiring physical or remote console access to reboot the affected system.

🟠

Likely Case

System crash during network interface configuration changes or driver initialization, causing temporary service disruption.

🟢

If Mitigated

No impact if patched or if MANA driver is not in use.

🌐 Internet-Facing: LOW - Requires local access or ability to trigger network interface changes.

🏢 Internal Only: MEDIUM - Could be triggered by legitimate administrative actions or automated configuration changes.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires ability to trigger network queue creation/destruction, typically through privileged operations or driver initialization.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel with fixes from stable commits referenced in CVE

Vendor Advisory: https://git.kernel.org/stable/c/386617efacab10bf5bb40bde403467c57cc00470

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing fixes 2. Reboot system 3. Verify MANA driver loads without errors

🔧 Temporary Workarounds

Disable MANA driver

linux

Prevent loading of vulnerable MANA driver module

echo 'blacklist mana' >> /etc/modprobe.d/blacklist.conf
rmmod mana
update-initramfs -u

🧯 If You Can't Patch

Avoid network interface configuration changes on systems using MANA driver
Monitor system logs for kernel panic events related to MANA driver

🔍 How to Verify

Check if Vulnerable:

Check if MANA driver is loaded: lsmod | grep mana && check kernel version against patched versions

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fixes and MANA driver loads without errors during network operations

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages containing 'mana_destroy_rxq' or 'napi_disable'
System crash/reboot events

Network Indicators:

Network interface failures on Azure VMs with MANA

SIEM Query:

event_source:kernel AND (message:"mana_destroy_rxq" OR message:"napi_disable")

📊 Metadata

CVE ID: CVE-2024-46784

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-908

Published: September 18, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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