CVE-2023-52673
📋 TL;DR
This CVE describes a null pointer dereference vulnerability in the AMD display driver within the Linux kernel. When accessing debugfs, the system attempts to call a callback function that may not exist, causing a kernel panic or system crash. This affects Linux systems with AMD graphics hardware using vulnerable kernel versions.
💻 Affected Systems
- Linux kernel with AMD display driver (drm/amd/display)
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially causing data loss or system instability.
Likely Case
System crash or kernel panic when accessing debugfs interfaces related to AMD display functionality.
If Mitigated
Minor system instability or debugfs access failures if proper access controls limit debugfs exposure.
🎯 Exploit Status
Requires local access and knowledge of debugfs interface. Likely discovered through code audit/fuzzing.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 43235db21fc23559f50a62f8f273002eeb506f5a and efb91fea652a42fcc037d2a9ef4ecd1ffc5ff4b7
Vendor Advisory: https://git.kernel.org/stable/c/43235db21fc23559f50a62f8f273002eeb506f5a
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Reboot system. 3. Verify kernel version and that AMD display driver loads correctly.
🔧 Temporary Workarounds
Disable debugfs
linuxMount debugfs with noexec or disable it entirely to prevent access
mount -o remount,noexec /sys/kernel/debug
echo 0 > /sys/kernel/debug/dri/0/amdgpu_dm_debugfs
Restrict debugfs access
linuxLimit debugfs access to privileged users only
chmod 700 /sys/kernel/debug
setfacl -m u:root:rwx /sys/kernel/debug
🧯 If You Can't Patch
- Restrict access to debugfs filesystem to root only
- Disable AMD display driver debug features if possible
🔍 How to Verify
Check if Vulnerable:
Check if kernel version is vulnerable by examining kernel source or checking if /sys/kernel/debug/dri/*/amdgpu_dm_debugfs exists and system has AMD graphicsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits and test debugfs access without system crash📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference in kernel logs
- AMD display driver crash logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer" OR "kernel panic" OR "amdgpu" OR "drm/amd/display")