CVE-2024-42102 – This CVE addresses a potential divide-by-zero v... (How to Fix)

Q: What is the severity of CVE-2024-42102?

CVE-2024-42102 has a CVSS score of 4.7 (MEDIUM). This CVE addresses a potential divide-by-zero vulnerability in the Linux kernel's writeback mechanism that could cause kernel panics or system instability. The vulnerability affects Linux systems where dirty page thresholds exceed 32-bit limits, potentially leading to denial of service. Systems with 4GB+ RAM using default settings are particularly susceptible.

📋 TL;DR

This CVE addresses a potential divide-by-zero vulnerability in the Linux kernel's writeback mechanism that could cause kernel panics or system instability. The vulnerability affects Linux systems where dirty page thresholds exceed 32-bit limits, potentially leading to denial of service. Systems with 4GB+ RAM using default settings are particularly susceptible.

💻 Affected Systems

Products:

Linux Kernel

Versions: Specific versions between the vulnerable commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78 and its revert

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Systems with 4GB+ RAM using default dirty page settings are most vulnerable. The issue primarily affects 32-bit architectures but can also impact 64-bit systems.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially requiring physical intervention to restore functionality.

🟠

Likely Case

System instability, performance degradation, or occasional crashes when dirty page thresholds are exceeded during writeback operations.

🟢

If Mitigated

Minor performance impact or no noticeable effect if system memory usage remains below threshold triggers.

🌐 Internet-Facing: LOW - This is a local kernel vulnerability requiring local access; not directly exploitable over network.

🏢 Internal Only: MEDIUM - Local users or processes could potentially trigger the condition leading to system instability affecting all users.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Exploitation requires local access and ability to manipulate dirty page thresholds. This is more likely to be triggered accidentally than maliciously exploited.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions with commit reversion (see provided git.kernel.org references)

Vendor Advisory: https://git.kernel.org/stable/c/000099d71648504fb9c7a4616f92c2b70c3e44ec

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from official distribution repositories. 2. Reboot system to load new kernel. 3. Verify kernel version matches patched release.

🔧 Temporary Workarounds

Adjust dirty page thresholds

linux

Reduce dirty page thresholds below overflow trigger points

sysctl -w vm.dirty_background_ratio=5
sysctl -w vm.dirty_ratio=10

🧯 If You Can't Patch

Implement workaround by adjusting vm.dirty_background_ratio and vm.dirty_ratio sysctl parameters
Monitor system memory usage and avoid memory-intensive operations that could trigger threshold conditions

🔍 How to Verify

Check if Vulnerable:

Check kernel version and compare against affected range. Use: uname -r and check if between vulnerable commit and fix.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version matches patched release and check that commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78 is reverted.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
'divide error' in kernel logs
System crash/reboot events

Network Indicators:

None - this is a local kernel issue

SIEM Query:

source="kernel" AND ("divide error" OR "panic" OR "Oops")

📊 Metadata

CVE ID: CVE-2024-42102

CVSS v3 Score: 4.7 (MEDIUM)

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

CWE: CWE-369

Published: July 30, 2024

Last Updated: November 3, 2025

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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