CVE-2022-48942
📋 TL;DR
A NULL pointer dereference vulnerability in the Linux kernel's hardware monitoring (hwmon) subsystem occurs when sensor registration with a thermal zone fails, causing kernel crashes. This affects Linux systems using hwmon sensors with thermal zone integration. The vulnerability can lead to denial of service through system crashes.
💻 Affected Systems
- Linux kernel
📦 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 complete system crash and denial of service, requiring physical or remote reboot.
Likely Case
System instability or crashes when hwmon sensors fail to register with thermal zones, causing service disruption.
If Mitigated
Minor performance impact or sensor functionality limitations with proper error handling.
🎯 Exploit Status
Exploitation requires triggering specific hwmon sensor registration failures. Likely requires local access or ability to manipulate hardware monitoring events.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel versions via provided git commits
Vendor Advisory: https://git.kernel.org/stable/c/1b5f517cca36292076d9e38fa6e33a257703e62e
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable hwmon thermal zone integration
linuxPrevent hwmon sensors from registering with thermal zones if not required
echo 0 > /sys/class/hwmon/hwmon*/temp*_enable
Note: Commands vary by hardware and may impact thermal management
🧯 If You Can't Patch
- Restrict local user access to prevent potential exploitation
- Monitor system logs for hwmon errors or kernel crashes
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions. Examine dmesg for hwmon/thermal registration errors.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes commit 1b5f517cca36292076d9e38fa6e33a257703e62e or related patches. Test hwmon sensor functionality.📡 Detection & Monitoring
Log Indicators:
- Kernel NULL pointer dereference errors
- hwmon registration failures
- thermal_zone_device_update crashes
- mutex_lock errors in call traces
Network Indicators:
- None - local vulnerability
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "hwmon" OR "thermal_zone" OR "mutex_lock" AND crash)