CVE-2022-49900
📋 TL;DR
A double-free vulnerability in the Linux kernel's i2c-piix4 driver causes memory corruption when the module is removed and reloaded. This allows local attackers to crash the system or potentially execute arbitrary code with kernel privileges. Systems using affected Linux kernel versions with the i2c-piix4 driver loaded are vulnerable.
💻 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 →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 privilege escalation to root via arbitrary code execution in kernel context.
Likely Case
System crash or kernel panic when i2c-piix4 module is removed and another i2c driver is loaded, causing denial of service.
If Mitigated
Limited to local users with module loading privileges; systems without i2c-piix4 loaded or with module loading restricted are protected.
🎯 Exploit Status
Exploitation requires local access and ability to load/unload kernel modules. The crash example shows a specific trigger sequence.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 569bea74c94d37785682b11bab76f557520477cd, bfd5e62f9a7ee214661cb6f143a3b40ccc63317f, d78ccdce662e88f41e87e90cf2bee63c1715d2a5, or fe51636fffc8108c7c4da6aa393010e786530ad9
Vendor Advisory: https://git.kernel.org/stable/c/569bea74c94d37785682b11bab76f557520477cd
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify i2c-piix4 module loads without issues.
🔧 Temporary Workarounds
Disable i2c-piix4 module
linuxPrevent loading of vulnerable driver module
echo 'blacklist i2c_piix4' >> /etc/modprobe.d/blacklist.conf
rmmod i2c_piix4
Restrict module loading
linuxPrevent unauthorized users from loading/unloading kernel modules
sysctl -w kernel.modules_disabled=1
echo 'kernel.modules_disabled=1' >> /etc/sysctl.conf
🧯 If You Can't Patch
- Restrict local user access to systems with vulnerable kernels
- Implement strict module loading policies and monitor for unauthorized module operations
🔍 How to Verify
Check if Vulnerable:
Check if i2c-piix4 module is loaded: lsmod | grep i2c_piix4Check Version:
uname -rVerify Fix Applied:
Check kernel version against patched versions from your distribution, and test module removal/reload: rmmod i2c_piix4 && modprobe i2c_piix4📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages related to i2c-piix4
- Page fault errors at address ffffffffc053d860
- Failed module operations in system logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
search 'kernel: BUG: unable to handle page fault' OR 'i2c_piix4' OR 'piix4_remove' in system logs