CVE-2024-47756 – This CVE-2024-47756 is a NULL pointer dereferen... (How to Fix)

Q: What is the severity of CVE-2024-47756?

CVE-2024-47756 has a CVSS score of 5.5 (MEDIUM). This CVE-2024-47756 is a NULL pointer dereference vulnerability in the Linux kernel's PCI keystone driver. The bug occurs when an incorrect logical operator (&& instead of ||) in ks_pcie_quirk() could lead to dereferencing a NULL pointer, potentially causing kernel panic or system crash. This affects systems using the affected Linux kernel versions with the keystone PCI driver enabled.

📋 TL;DR

This CVE-2024-47756 is a NULL pointer dereference vulnerability in the Linux kernel's PCI keystone driver. The bug occurs when an incorrect logical operator (&& instead of ||) in ks_pcie_quirk() could lead to dereferencing a NULL pointer, potentially causing kernel panic or system crash. This affects systems using the affected Linux kernel versions with the keystone PCI driver enabled.

💻 Affected Systems

Products:

Linux kernel

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

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when the keystone PCI driver is loaded and specific hardware conditions are met. This driver is typically used with Texas Instruments Keystone SoCs.

📦 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 →

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 reboot of affected systems.

🟠

Likely Case

System instability or crash when specific PCI operations are performed on affected hardware configurations.

🟢

If Mitigated

No impact if the vulnerable driver is not loaded or the specific hardware configuration is not present.

🌐 Internet-Facing: LOW - This is a local kernel vulnerability requiring local access or specific hardware interaction.

🏢 Internal Only: MEDIUM - Could affect internal servers and workstations with the vulnerable driver loaded, potentially causing service disruption.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and specific hardware conditions. The vulnerability is a logic error that could be triggered during normal PCI operations.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check specific kernel versions in provided git commit references

Vendor Advisory: https://git.kernel.org/stable/c/2171c5cb2fbc3e03af7e8116cd58736c09328655

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version. 2. Rebuild kernel if compiling from source. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable keystone PCI driver

linux

Prevent loading of the vulnerable driver module

echo 'blacklist keystone-pcie' >> /etc/modprobe.d/blacklist.conf
rmmod keystone-pcie

🧯 If You Can't Patch

Ensure the keystone PCI driver is not loaded on affected systems
Restrict physical access to systems and monitor for kernel panic events

🔍 How to Verify

Check if Vulnerable:

Check if keystone-pcie module is loaded: lsmod | grep keystone-pcie

Check Version:

uname -r

Verify Fix Applied:

Check kernel version after update: uname -r and verify it includes the fix commit

📡 Detection & Monitoring

Log Indicators:

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

Network Indicators:

None - this is a local vulnerability

SIEM Query:

Search for 'kernel panic' or 'NULL pointer dereference' in system logs

📊 Metadata

CVE ID: CVE-2024-47756

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: October 21, 2024

Last Updated: November 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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