CVE-2025-38240 – This vulnerability is a NULL pointer dereferenc... (How to Fix)

Q: What is the severity of CVE-2025-38240?

CVE-2025-38240 has a CVSS score of 5.5 (MEDIUM). This vulnerability is a NULL pointer dereference in the Linux kernel's MediaTek DisplayPort driver. It occurs when error logging functions attempt to access an uninitialized DRM device pointer during hot-plug detection, potentially causing a kernel panic. Systems using affected MediaTek hardware with the Linux kernel are vulnerable.

📋 TL;DR

This vulnerability is a NULL pointer dereference in the Linux kernel's MediaTek DisplayPort driver. It occurs when error logging functions attempt to access an uninitialized DRM device pointer during hot-plug detection, potentially causing a kernel panic. Systems using affected MediaTek hardware with the Linux kernel are vulnerable.

💻 Affected Systems

Products:

Linux kernel with MediaTek DisplayPort driver

Versions: Linux kernel versions containing the vulnerable code (specific versions not specified in CVE, but patches exist for multiple stable branches)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires MediaTek hardware with DisplayPort support and the mtk-dp driver loaded.

📦 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 →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, requiring physical or remote reboot.

🟠

Likely Case

System instability or crash when DisplayPort devices are connected/disconnected, causing temporary denial of service.

🟢

If Mitigated

Minor system disruption during display operations, with automatic recovery possible.

🌐 Internet-Facing: LOW - Requires local access to trigger via hardware interaction.

🏢 Internal Only: MEDIUM - Could affect workstations/servers with MediaTek graphics during normal display operations.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires physical or local access to trigger via DisplayPort hot-plug events. No remote exploitation vector identified.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Multiple stable kernel versions with commits: 106a6de46cf4, 13ec849fd2ea, 149a5c38436c, 2fda391ef7a7, 57a9fb47551b

Vendor Advisory: https://git.kernel.org/stable/c/106a6de46cf4887d535018185ec528ce822d6d84

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution. 2. For custom kernels, apply the relevant commit from kernel.org. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable MediaTek DP driver

linux

Prevent loading of the vulnerable driver module

echo 'blacklist mtk-dp' >> /etc/modprobe.d/blacklist.conf
rmmod mtk-dp

Avoid DisplayPort hot-plug

all

Prevent triggering the vulnerable code path by avoiding DisplayPort connection changes

🧯 If You Can't Patch

Restrict physical access to DisplayPort ports to prevent hot-plug events
Monitor system logs for kernel panic events related to mtk-dp driver

🔍 How to Verify

Check if Vulnerable:

Check if mtk-dp kernel module is loaded: lsmod | grep mtk_dp && check kernel version against patched versions

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes one of the fix commits: grep -r '106a6de46cf4\|13ec849fd2ea\|149a5c38436c\|2fda391ef7a7\|57a9fb47551b' /usr/src/linux/

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages containing 'mtk_dp' or 'NULL pointer dereference'
dmesg errors showing mtk-dp driver failures

Network Indicators:

None - local hardware vulnerability

SIEM Query:

source="kernel" AND ("mtk_dp" OR "NULL pointer" OR "kernel panic")

📊 Metadata

CVE ID: CVE-2025-38240

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

EPSS Score: 0.06% exploit probability (19.4th percentile)

Published: April 18, 2025

Last Updated: November 6, 2025

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2025-38240, you might also want to check these: