CVE-2024-43894 – This CVE describes a NULL pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2024-43894?

CVE-2024-43894 has a CVSS score of 5.5 (MEDIUM). This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's Direct Rendering Manager (DRM) client subsystem. When drm_mode_duplicate() fails in drm_client_modeset_probe(), the system may crash due to dereferencing a NULL pointer. This affects Linux systems using DRM graphics drivers.

📋 TL;DR

This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's Direct Rendering Manager (DRM) client subsystem. When drm_mode_duplicate() fails in drm_client_modeset_probe(), the system may crash due to dereferencing a NULL pointer. This affects Linux systems using DRM graphics drivers.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected kernel versions not specified in CVE description; check git commits for exact ranges

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires DRM client functionality to be active; affects systems with graphics hardware using DRM drivers.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially causing data loss or system instability.

🟠

Likely Case

System crash or kernel panic when specific graphics operations fail, resulting in temporary denial of service.

🟢

If Mitigated

Minor system instability that requires reboot to recover normal operation.

🌐 Internet-Facing: LOW - This vulnerability requires local access or specific graphics subsystem interaction, not directly exploitable over network.

🏢 Internal Only: MEDIUM - Local users or processes with appropriate privileges could trigger the crash, affecting system availability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires triggering the specific failure condition in drm_mode_duplicate() function.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check provided git commit hashes for specific kernel versions

Vendor Advisory: https://git.kernel.org/stable/c/113fd6372a5bb3689aba8ef5b8a265ed1529a78f

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable affected DRM functionality

linux

Disable DRM client modesetting if not required

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

🧯 If You Can't Patch

Restrict local user access to minimize potential triggers
Monitor system logs for kernel panic events related to DRM

🔍 How to Verify

Check if Vulnerable:

Check kernel version against patched commits: uname -r and compare with git commit history

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes one of the fix commits: 113fd6372a5bb3689aba8ef5b8a265ed1529a78f or others listed

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
NULL pointer dereference in DRM subsystem logs
System crash/reboot events

Network Indicators:

None - local vulnerability

SIEM Query:

source="kernel" AND ("NULL pointer dereference" OR "drm_client_modeset_probe" OR "kernel panic")

📊 Metadata

CVE ID: CVE-2024-43894

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: August 26, 2024

Last Updated: November 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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