CVE-2022-49328
📋 TL;DR
This is a use-after-free vulnerability in the Linux kernel's mt76 wireless driver that allows an attacker to potentially execute arbitrary code or cause a kernel crash. It affects systems using MediaTek Wi-Fi chips with vulnerable kernel versions. The vulnerability occurs when the driver improperly handles station information pointers during connection/disconnection events.
💻 Affected Systems
- Linux kernel with mt76 wireless driver
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash, or potential arbitrary code execution with kernel privileges resulting in complete system compromise.
Likely Case
System instability, kernel crashes, or denial of service affecting Wi-Fi connectivity on affected devices.
If Mitigated
With proper kernel protections (KASAN, KPTI), crashes are contained but Wi-Fi functionality may still be disrupted.
🎯 Exploit Status
Exploitation requires Wi-Fi access and knowledge of driver internals. No public exploits known as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 4448327b41738dbfcda680eb4935ff835568f468, 51fb1278aa57ae0fc54adaa786e1965362bed4fb, d5f77f1dbb59feae81f88e44551e8e1d8a802d9a, e55bcdd0bf34a8b10d45ce80ebb3164c5292a17d
Vendor Advisory: https://git.kernel.org/stable/c/4448327b41738dbfcda680eb4935ff835568f468
Restart Required: No
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Rebuild kernel if compiling from source with the fix commits included.
🔧 Temporary Workarounds
Disable Wi-Fi interface
allTemporarily disable the affected Wi-Fi interface to prevent exploitation
sudo ip link set wlan0 down
sudo nmcli radio wifi off
Blacklist mt76 module
allPrevent loading of the vulnerable mt76 driver module
echo 'blacklist mt76' | sudo tee /etc/modprobe.d/blacklist-mt76.conf
sudo update-initramfs -u
🧯 If You Can't Patch
- Disable Wi-Fi functionality on affected systems
- Implement network segmentation to isolate systems with vulnerable Wi-Fi hardware
- Monitor for kernel panic logs and Wi-Fi disconnection events
🔍 How to Verify
Check if Vulnerable:
Check if mt76 module is loaded: lsmod | grep mt76. Check kernel version against distribution's security advisories.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits. Check dmesg for absence of mt76-related use-after-free errors.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KASAN use-after-free reports in dmesg
- mt76 driver error messages
- Wi-Fi disconnection events
Network Indicators:
- Unexpected Wi-Fi disconnections
- Increased authentication/deauthentication frames
SIEM Query:
source="kernel" AND ("mt76" OR "KASAN: use-after-free" OR "BUG: KASAN")