CVE-2024-35919 – This CVE describes a NULL pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2024-35919?

CVE-2024-35919 has a CVSS score of 7.0 (HIGH). This CVE describes a NULL pointer dereference vulnerability in the MediaTek video codec driver of the Linux kernel. When the encoder context list is deleted unexpectedly due to SCP IP block issues, the vpu_enc_ipi_handler function can access a NULL pointer, potentially causing kernel crashes or instability. This affects Linux systems using MediaTek video codec hardware.

📋 TL;DR

This CVE describes a NULL pointer dereference vulnerability in the MediaTek video codec driver of the Linux kernel. When the encoder context list is deleted unexpectedly due to SCP IP block issues, the vpu_enc_ipi_handler function can access a NULL pointer, potentially causing kernel crashes or instability. This affects Linux systems using MediaTek video codec hardware.

💻 Affected Systems

Products:

Linux kernel with MediaTek video codec driver

Versions: Linux kernel versions before the fix commits (specific versions depend on distribution backports)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with MediaTek video codec hardware and the mediatek-vcodec 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 →

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, denial of service, or potential privilege escalation if combined with other vulnerabilities.

🟠

Likely Case

System instability, application crashes, or denial of service affecting video encoding functionality.

🟢

If Mitigated

Minor performance impact from added locking mechanism with no security impact.

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

🏢 Internal Only: MEDIUM - Could be exploited by local users or malicious processes to cause system instability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires ability to trigger video encoding operations and timing conditions where ctx_list is deleted while being accessed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel with commits 41671f0c0182b2bae74ca7e3b0f155559e3e2fc5 and 51c84a8aac6e3b59af2b0e92ba63cabe2e641a2d

Vendor Advisory: https://git.kernel.org/stable/c/41671f0c0182b2bae74ca7e3b0f155559e3e2fc5

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. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable MediaTek video codec module

linux

Prevent loading of vulnerable driver module

echo 'blacklist mediatek-vcodec' >> /etc/modprobe.d/blacklist.conf
rmmod mediatek-vcodec

🧯 If You Can't Patch

Restrict access to video encoding functionality to trusted users only
Monitor system logs for kernel panic or oops messages related to vpu_enc_ipi_handler

🔍 How to Verify

Check if Vulnerable:

Check if mediatek-vcodec module is loaded: lsmod | grep mediatek-vcodec && check kernel version against patched versions

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits: grep -q '41671f0c0182b2bae74ca7e3b0f155559e3e2fc5\|51c84a8aac6e3b59af2b0e92ba63cabe2e641a2d' /proc/version

📡 Detection & Monitoring

Log Indicators:

Kernel oops messages
NULL pointer dereference in vpu_enc_ipi_handler
System crashes during video encoding

Network Indicators:

None - local vulnerability only

SIEM Query:

source="kernel" AND ("NULL pointer dereference" OR "vpu_enc_ipi_handler" OR "mediatek-vcodec")

📊 Metadata

CVE ID: CVE-2024-35919

CVSS v3 Score: 7.0 (HIGH)

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

CWE: CWE-476

Published: May 19, 2024

Last Updated: April 4, 2025

🔗 References

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🔗 Related Vulnerabilities

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