CVE-2025-38543 – This CVE is a NULL pointer dereference vulnerab... (How to Fix)

Q: What is the severity of CVE-2025-38543?

CVE-2025-38543 has a CVSS score of 5.5 (MEDIUM). This CVE is a NULL pointer dereference vulnerability in the Linux kernel's NVIDIA Tegra NVDEC driver. It occurs when dma_alloc_coherent fails to allocate memory but the return value isn't properly checked, potentially causing kernel crashes or denial of service. Systems using affected Linux kernel versions with Tegra graphics hardware are vulnerable.

📋 TL;DR

This CVE is a NULL pointer dereference vulnerability in the Linux kernel's NVIDIA Tegra NVDEC driver. It occurs when dma_alloc_coherent fails to allocate memory but the return value isn't properly checked, potentially causing kernel crashes or denial of service. Systems using affected Linux kernel versions with Tegra graphics hardware are vulnerable.

💻 Affected Systems

Products:

Linux kernel with NVIDIA Tegra NVDEC driver

Versions: Specific kernel versions containing the vulnerable code (check git commits for exact ranges)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with NVIDIA Tegra hardware using the NVDEC driver. Virtual machines without Tegra hardware are not affected.

📦 What is this software?

Debian Linux by Debian

View all CVEs affecting Debian Linux →

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 requiring physical access to restart the system.

🟠

Likely Case

System instability or crash when the NVDEC driver attempts to allocate DMA memory under specific conditions, causing denial of service.

🟢

If Mitigated

Minor performance impact from proper error handling with no security implications.

🌐 Internet-Facing: LOW - Requires local access or ability to trigger specific driver operations.

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

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires triggering specific memory allocation failure conditions in the NVDEC driver, which may require local access and specific hardware/driver usage patterns.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the fix commits: 2e0812eedccd0629d73c9d0b1184a5db055df1da and related

Vendor Advisory: https://git.kernel.org/stable/c/2e0812eedccd0629d73c9d0b1184a5db055df1da

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable NVDEC driver module

linux

Prevent loading of the vulnerable nvdec driver module

echo 'blacklist tegra-nvdec' >> /etc/modprobe.d/blacklist.conf
rmmod tegra-nvdec

🧯 If You Can't Patch

Restrict local user access to systems with Tegra hardware
Monitor system logs for kernel panic or oops messages related to nvdec driver

🔍 How to Verify

Check if Vulnerable:

Check if tegra-nvdec module is loaded: lsmod | grep nvdec AND check kernel version against vulnerable ranges

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits: grep -q '2e0812eedccd0629d73c9d0b1184a5db055df1da' /proc/version_signature (if available) OR check distribution kernel changelog

📡 Detection & Monitoring

Log Indicators:

Kernel oops messages mentioning nvdec
System crash/panic logs
dmesg output showing NULL pointer dereference in nvdec

Network Indicators:

None - local vulnerability only

SIEM Query:

source="kernel" AND ("nvdec" OR "NULL pointer dereference")

📊 Metadata

CVE ID: CVE-2025-38543

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: 0.02% exploit probability (2.6th percentile)

Published: August 16, 2025

Last Updated: January 7, 2026

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2025-38543, you might also want to check these: