CVE-2023-52844 – This CVE describes a NULL pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2023-52844?

CVE-2023-52844 has a CVSS score of 6.2 (MEDIUM). This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's vidtv media driver PSI component. If kstrdup() fails to allocate memory and returns NULL, the code proceeds to use this NULL pointer, causing a kernel crash. This affects systems running vulnerable Linux kernel versions with the vidtv driver loaded.

📋 TL;DR

This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's vidtv media driver PSI component. If kstrdup() fails to allocate memory and returns NULL, the code proceeds to use this NULL pointer, causing a kernel crash. This affects systems running vulnerable Linux kernel versions with the vidtv driver loaded.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific vulnerable kernel versions referenced in the git commits (exact range depends on distribution backports)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if the CONFIG_VIDEO_VIDTV kernel module is compiled and loaded. Many distributions don't enable this by default.

📦 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 and denial of service, potentially causing data loss or service disruption.

🟠

Likely Case

Local denial of service through kernel crash when specific conditions trigger the memory allocation failure.

🟢

If Mitigated

Minimal impact if system has proper memory management and the vidtv driver isn't actively used.

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

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

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires ability to trigger the specific code path and cause kstrdup() to fail, which typically requires memory pressure or specific conditions.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the referenced git commits (e.g., 3387490c89b10aeb4e71d78b65dbc9ba4b2385b9)

Vendor Advisory: https://git.kernel.org/stable/c/3387490c89b10aeb4e71d78b65dbc9ba4b2385b9

Restart Required: Yes

Instructions:

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

🔧 Temporary Workarounds

Unload vidtv module

linux

Remove the vulnerable kernel module if not needed

sudo rmmod vidtv

Blacklist vidtv module

linux

Prevent vidtv module from loading at boot

echo 'blacklist vidtv' | sudo tee /etc/modprobe.d/blacklist-vidtv.conf

🧯 If You Can't Patch

Ensure CONFIG_VIDEO_VIDTV is not enabled in kernel configuration
Implement strict memory limits to reduce chance of kstrdup() failure

🔍 How to Verify

Check if Vulnerable:

Check if vidtv module is loaded: lsmod | grep vidtv. Check kernel version against patched versions.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and vidtv module version matches patched source.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/kern.log or dmesg
NULL pointer dereference errors in kernel logs

Network Indicators:

None - local vulnerability

SIEM Query:

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

📊 Metadata

CVE ID: CVE-2023-52844

CVSS v3 Score: 6.2 (MEDIUM)

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

CWE: CWE-476

Published: May 21, 2024

Last Updated: April 2, 2025

🔗 References

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🔗 Related Vulnerabilities

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