CVE-2022-49187
📋 TL;DR
A NULL pointer dereference vulnerability in the Linux kernel's clock framework allows local attackers to cause a kernel panic (system crash) by triggering specific clock operations. This affects Linux systems where clock hardware is registered without an associated device pointer, which is a common practice in kernel development. The vulnerability requires local access to execute.
💻 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
Local privilege escalation leading to full system compromise if combined with other vulnerabilities, or denial of service through kernel panic causing system reboot.
Likely Case
Local denial of service through kernel panic, requiring physical or remote console access to restore system functionality.
If Mitigated
Minimal impact with proper access controls preventing unauthorized local users from executing privileged clock operations.
🎯 Exploit Status
Requires local access and ability to trigger specific clock framework operations. Exploit would need to identify and access vulnerable clock hardware instances.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 0c1b56df451716ba207bbf59f303473643eee4fd, 23f89fe005b105f0dcc55034c13eb89f9b570fac, 4be3e4c05d8dd1b83b75652cad88c9e752ec7054, d183f20cf5a7b546d4108e796b98210ceb317579
Vendor Advisory: https://git.kernel.org/stable/c/0c1b56df451716ba207bbf59f303473643eee4fd
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. For custom kernels, apply the fix commits to your kernel source. 3. Recompile and install the updated kernel. 4. Reboot the system to load the patched kernel.
🔧 Temporary Workarounds
Restrict local user access
linuxLimit access to system to trusted users only, preventing unauthorized local users from triggering the vulnerability
Disable unnecessary clock hardware
linuxIf specific clock hardware drivers are not needed, blacklist or disable them to reduce attack surface
echo 'blacklist driver_name' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized local users from accessing the system
- Monitor system logs for kernel panic events and implement automated alerting for denial of service attempts
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with distribution's security advisories. Vulnerable if using kernel version before the fix commits.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to patched version and check that system doesn't crash when performing clock operations.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg output
- System crash/reboot events without clear cause
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kern.log" AND "kernel panic" OR "NULL pointer dereference"