CVE-2022-50178
📋 TL;DR
A division-by-zero vulnerability in the Linux kernel's rtw89 WiFi driver for Realtek 8852A chipsets can cause kernel panics when processing certain RF calibration results. This affects Linux systems using vulnerable WiFi hardware and drivers, potentially causing denial of service during WiFi connection establishment.
💻 Affected Systems
- Linux kernel with rtw89 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, requiring physical or remote reboot.
Likely Case
System crash or instability when connecting to WiFi networks, particularly during authentication/association phases.
If Mitigated
Minor service interruption if system automatically recovers from kernel panic, but potential data loss in active connections.
🎯 Exploit Status
Exploitation requires ability to trigger RF calibration with specific negative results. Stack trace shows wpa_supplicant process triggering it, suggesting WiFi authentication/association could trigger it.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 065e83ac83c0c0e615b96947145c85c4bd76c09a, 5abc81a138f873ab55223ec674afc3a3f945d60f, or 683a4647a7a3044868cfdc14c117525091b9fa0c
Vendor Advisory: https://git.kernel.org/stable/c/065e83ac83c0c0e615b96947145c85c4bd76c09a
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Reboot system to load new kernel. 3. Verify rtw89 driver is updated.
🔧 Temporary Workarounds
Disable rtw89 driver
linuxBlacklist or disable the rtw89 driver to prevent loading
echo 'blacklist rtw89_core' >> /etc/modprobe.d/blacklist-rtw89.conf
update-initramfs -u
reboot
Use alternative WiFi hardware
linuxReplace Realtek 8852A hardware with different WiFi chipset
🧯 If You Can't Patch
- Disable WiFi functionality on affected systems
- Implement network segmentation to limit WiFi access to trusted devices only
🔍 How to Verify
Check if Vulnerable:
Check if system uses rtw89 driver: lsmod | grep rtw89. Check kernel version: uname -r and compare with patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits. Check dmesg for absence of 'divide error' messages related to rtw8852a_dpk.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages with 'divide error'
- Stack traces containing 'rtw8852a_dpk'
- wpa_supplicant crashes during authentication
Network Indicators:
- WiFi connection failures on affected hardware
- Unexpected system reboots during WiFi operations
SIEM Query:
source="kernel" AND ("divide error" OR "rtw8852a_dpk")