CVE-2025-21985
📋 TL;DR
This CVE describes an out-of-bounds memory access vulnerability in the AMD display driver component of the Linux kernel. Attackers could exploit this to cause kernel crashes or potentially execute arbitrary code with kernel privileges. All Linux systems using affected AMD GPU hardware with the vulnerable driver are at risk.
💻 Affected Systems
- Linux kernel with AMD GPU 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 →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, system compromise, and potential persistence.
Likely Case
Kernel panic or system crash causing denial of service, potentially requiring physical access to restart.
If Mitigated
Limited to denial of service if exploit fails or system has additional memory protection mechanisms.
🎯 Exploit Status
Requires local access to trigger the vulnerable code path. Exploitation depends on specific AMD GPU hardware and driver state.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel stable releases containing commits 36793d90d76f, 8adbb2a98b00, and 9aedc776b110
Vendor Advisory: https://git.kernel.org/stable/c/36793d90d76f667d26c6dd025571481ee0c96abc
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from distribution repositories. 2. Reboot system to load new kernel. 3. Verify kernel version matches patched release.
🔧 Temporary Workarounds
Disable AMD GPU driver module
linuxPrevent loading of vulnerable AMD display driver module
echo 'blacklist amdgpu' >> /etc/modprobe.d/blacklist-amdgpu.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict physical and remote access to affected systems
- Implement strict privilege separation and limit user access to GPU functionality
🔍 How to Verify
Check if Vulnerable:
Check if AMD GPU is present and kernel version is unpatched: lspci | grep -i amd && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits: grep -r '36793d90d76f\|8adbb2a98b00\|9aedc776b110' /usr/src/linux-headers-$(uname -r)/📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- AMDGPU driver crash logs in dmesg
- System crash/panic logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("AMDGPU" OR "drm/amd/display") AND ("panic" OR "oops" OR "segfault")