CVE-2024-40974 – This CVE describes a buffer overflow vulnerabil... (How to Fix)

Q: What is the severity of CVE-2024-40974?

CVE-2024-40974 has a CVSS score of 7.8 (HIGH). This CVE describes a buffer overflow vulnerability in the Linux kernel's powerpc/pseries hypercall functions. The vulnerability allows stack corruption when incorrect buffer sizes are passed to hypercall APIs, potentially leading to kernel crashes or arbitrary code execution. Systems running Linux kernels with PowerPC pSeries architecture are affected.

📋 TL;DR

This CVE describes a buffer overflow vulnerability in the Linux kernel's powerpc/pseries hypercall functions. The vulnerability allows stack corruption when incorrect buffer sizes are passed to hypercall APIs, potentially leading to kernel crashes or arbitrary code execution. Systems running Linux kernels with PowerPC pSeries architecture are affected.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE description; check kernel commit history for vulnerable versions before fixes.

Operating Systems: Linux distributions with PowerPC pSeries support

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using PowerPC pSeries architecture with hypercall functionality. Requires specific buggy code calling plpar_hcall functions with incorrect buffer sizes.

📦 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, system crash, or potential arbitrary code execution with kernel privileges leading to complete system compromise.

🟠

Likely Case

Kernel crash or system instability due to stack corruption, resulting in denial of service.

🟢

If Mitigated

No impact if proper buffer sizes are used or the vulnerability is patched.

🌐 Internet-Facing: LOW - Requires local access or ability to execute code on the system.

🏢 Internal Only: MEDIUM - Could be exploited by malicious local users or through other vulnerabilities that provide code execution.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: HIGH - Requires specific conditions: PowerPC pSeries architecture, vulnerable kernel version, and buggy code calling affected functions.

The CVE description mentions this is a contrived example and no real instances have been found. Exploitation requires specific programming errors in kernel code.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check specific kernel versions containing commits: 19c166ee42cf16d8b156a6cb4544122d9a65d3ca, 262e942ff5a839b9e4f3302a8987928b0c8b8a2d, 3ad0034910a57aa88ed9976b1431b7b8c84e0048, 8aa11aa001576bf3b00dcb8559564ad7a3113588, a8c988d752b3d98d5cc1e3929c519a55ef55426c

Vendor Advisory: https://git.kernel.org/stable/c/19c166ee42cf16d8b156a6cb4544122d9a65d3ca

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fixes. 2. Reboot system. 3. Verify kernel version after reboot.

🔧 Temporary Workarounds

Enable compiler warnings

linux

Compile kernel with -Warray-bounds flag to detect buffer size mismatches at compile time.

Add -Warray-bounds to compiler flags during kernel build

🧯 If You Can't Patch

Restrict access to PowerPC pSeries systems to trusted users only
Monitor system logs for kernel panics or unusual behavior

🔍 How to Verify

Check if Vulnerable:

Check kernel version and verify if it contains the vulnerable code. Examine kernel source for plpar_hcall function implementations.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version contains the fix commits. Check that plpar_hcall functions use explicitly-sized array parameters.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
Stack corruption errors in kernel logs
System crash/reboot events

Network Indicators:

None - local vulnerability only

SIEM Query:

source="kernel" AND ("panic" OR "stack corruption" OR "oops")

📊 Metadata

CVE ID: CVE-2024-40974

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-787

Published: July 12, 2024

Last Updated: November 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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