CVE-2022-50034
📋 TL;DR
This is a use-after-free vulnerability in the Linux kernel's USB CDNS3 gadget driver. An attacker could exploit this to cause a kernel crash (denial of service) or potentially execute arbitrary code. Systems running affected Linux kernel versions with USB gadget functionality enabled 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory corruption leading to arbitrary code execution with kernel privileges, potentially resulting in full system compromise.
Likely Case
Kernel panic or system crash causing denial of service, requiring system reboot.
If Mitigated
Limited impact if USB gadget functionality is disabled or system has kernel hardening protections.
🎯 Exploit Status
Requires local access or ability to connect USB devices. Exploitation requires triggering specific USB gadget operations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with fixes (see git references in CVE)
Vendor Advisory: https://git.kernel.org/stable/c/6d7ac60098b206d0472475b666cb09d556bec03d
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Rebuild kernel if compiling from source with the fix. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable USB gadget functionality
linuxDisable the vulnerable CDNS3 USB gadget driver if not needed
modprobe -r cdns3
echo 'blacklist cdns3' > /etc/modprobe.d/disable-cdns3.conf
🧯 If You Can't Patch
- Disable USB gadget functionality if not required
- Implement strict USB device control policies to prevent unauthorized USB connections
🔍 How to Verify
Check if Vulnerable:
Check if cdns3 module is loaded: lsmod | grep cdns3. Check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to patched version and cdns3 module loads without issues.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KFENCE use-after-free warnings in dmesg
- USB-related kernel crashes
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Search for: 'KFENCE: use-after-free' OR 'cdns3' AND 'panic' OR 'Oops' in kernel logs🔗 References
- https://git.kernel.org/stable/c/6d7ac60098b206d0472475b666cb09d556bec03d
- https://git.kernel.org/stable/c/6fd50446e7c9a98b4bcf96815f5c9602a16ea472
- https://git.kernel.org/stable/c/7d602f30149a117eea260208b1661bc404c21dfd
- https://git.kernel.org/stable/c/c3c1dbad3a2db32ecf371c97f2058491b8ba0f9a
- https://git.kernel.org/stable/c/e65d9b7147d7be3504893ca7dfb85286bda83d40
