CVE-2022-49234
📋 TL;DR
A vulnerability in the Linux kernel's Distributed Switch Architecture (DSA) subsystem allows array out-of-bounds accesses when VLAN filtering changes are incorrectly propagated across switches in multi-chip configurations. This can lead to kernel crashes or potential privilege escalation. Affected systems are those running Linux with DSA-enabled network switches in specific multi-chip topologies.
💻 Affected Systems
- Linux kernel with DSA subsystem
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash, potential privilege escalation if memory corruption can be controlled, and denial of service across all network services.
Likely Case
System crash or kernel panic when specific VLAN configuration changes occur on multi-chip DSA setups, causing temporary network disruption until system reboot.
If Mitigated
No impact if systems are not using DSA with multi-chip configurations or have applied the patch.
🎯 Exploit Status
Exploitation requires network configuration privileges and specific DSA multi-chip topology. The vulnerability is triggered by legitimate VLAN configuration operations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits 108dc8741c203e9d6ce4e973367f1bac20c7192b and e1f2a4dd8d433eec393d09273a78a3d3551339cf
Vendor Advisory: https://git.kernel.org/stable/c/108dc8741c203e9d6ce4e973367f1bac20c7192b
Restart Required: No
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager to update kernel package. 3. Rebuild kernel if using custom kernel. 4. No system restart required for DSA module, but kernel update requires reboot.
🔧 Temporary Workarounds
Disable VLAN filtering on DSA ports
Linux with DSAPrevent the vulnerable code path by disabling VLAN filtering on DSA switch ports
bridge vlan set dev <dsa_port> vlan_filtering 0
Avoid multi-chip DSA configurations
LinuxUse single-chip DSA setups or alternative network switching solutions
🧯 If You Can't Patch
- Restrict VLAN configuration privileges to trusted administrators only
- Monitor system logs for kernel panic events related to DSA operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if DSA is configured with multi-chip switches: 'uname -r' and examine /sys/class/net/ for DSA interfacesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits: 'grep -i "108dc8741c203e9d6ce4e973367f1bac20c7192b\|e1f2a4dd8d433eec393d09273a78a3d3551339cf" /proc/version'📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Out of bounds access errors in kernel logs
- DSA-related crash reports in dmesg
Network Indicators:
- Sudden loss of network connectivity on DSA-managed ports
- Bridge interface errors
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "general protection fault") AND ("dsa" OR "mv88e6xxx")