CVE-2024-35934 – This CVE describes a Linux kernel vulnerability... (How to Fix)

Q: What is the severity of CVE-2024-35934?

CVE-2024-35934 has a CVSS score of 5.5 (MEDIUM). This CVE describes a Linux kernel vulnerability in the SMC (Shared Memory Communications) subsystem where excessive rtnl (routing netlink) lock acquisition during network namespace creation causes performance degradation and potential deadlocks. Systems running affected Linux kernel versions with SMC enabled are vulnerable. The issue manifests as system instability rather than remote code execution.

📋 TL;DR

This CVE describes a Linux kernel vulnerability in the SMC (Shared Memory Communications) subsystem where excessive rtnl (routing netlink) lock acquisition during network namespace creation causes performance degradation and potential deadlocks. Systems running affected Linux kernel versions with SMC enabled are vulnerable. The issue manifests as system instability rather than remote code execution.

💻 Affected Systems

Products:

Linux kernel

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

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if SMC subsystem is enabled/compiled into the kernel. Many distributions may not have SMC enabled by default.

📦 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...

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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

System deadlock or kernel panic due to lock contention during concurrent network namespace operations, leading to denial of service.

🟠

Likely Case

Performance degradation, increased latency, and potential system instability during network namespace creation or modification operations.

🟢

If Mitigated

Minimal impact with proper kernel patching; systems without SMC enabled are unaffected.

🌐 Internet-Facing: LOW - This is primarily a local kernel issue affecting system stability rather than remote exploitation.

🏢 Internal Only: MEDIUM - Can cause system instability affecting services running on the host, but requires local operations or specific conditions.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires triggering specific network namespace operations; primarily a stability/DoS issue rather than privilege escalation or code execution.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits: 00af2aa93b76b1bade471ad0d0525d4d29ca5cc0, 6e920422e7104928f760fc0e12b6d65ab097a2e7, a2e6bffc0388526ed10406040279a693d62b36ec, b9117dc783c0ab0a3866812f70e07bf2ea071ac4, bc4d1ebca11b4f194e262326bd45938e857c59d2

Vendor Advisory: https://git.kernel.org/stable/c/00af2aa93b76b1bade471ad0d0525d4d29ca5cc0

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version matches patched release.

🔧 Temporary Workarounds

Disable SMC module

linux

Remove or blacklist SMC kernel module if not required

modprobe -r smc
echo 'blacklist smc' >> /etc/modprobe.d/blacklist.conf

🧯 If You Can't Patch

Avoid creating multiple network namespaces concurrently
Monitor system for lock contention warnings in kernel logs

🔍 How to Verify

Check if Vulnerable:

Check if SMC module is loaded: lsmod | grep smc AND check kernel version against patched releases

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits and test network namespace creation stability

📡 Detection & Monitoring

Log Indicators:

Kernel messages about rtnl lock contention
Warnings about smc_pnet_create_pnetids_list
High system latency during network operations

Network Indicators:

Increased network namespace creation failures

SIEM Query:

source="kernel" AND ("rtnl" OR "smc_pnet" OR "lock contention")

📊 Metadata

CVE ID: CVE-2024-35934

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

Published: May 19, 2024

Last Updated: December 17, 2025

🔗 References

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