CVE-2025-21990
📋 TL;DR
A NULL pointer dereference vulnerability in the AMD GPU driver of the Linux kernel could cause a kernel panic or system crash when handling PRT (Page Remapping Table) buffer objects without backing store. This affects systems with AMD graphics hardware running vulnerable Linux kernel versions. The vulnerability requires local access to exploit.
💻 Affected Systems
- Linux kernel with AMD GPU driver (drm/amdgpu)
📦 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 →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 and denial of service, potentially causing data loss or service disruption.
Likely Case
System crash or kernel panic when specific GPU operations are performed on PRT buffer objects without backing store.
If Mitigated
No impact if the system is patched or doesn't use affected AMD GPU hardware/drivers.
🎯 Exploit Status
Exploitation requires local access and knowledge of triggering the specific code path with PRT buffer objects. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commit 3e3fcd29b505cebed659311337ea03b7698767fc or later
Vendor Advisory: https://git.kernel.org/stable/c/6cc30748e17ea2a64051ceaf83a8372484e597f1
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commit. 2. Reboot the system to load the new kernel. 3. Verify the fix is applied by checking kernel version or commit hash.
🔧 Temporary Workarounds
Disable AMD GPU driver
linuxPrevent loading of the vulnerable amdgpu kernel module
echo 'blacklist amdgpu' >> /etc/modprobe.d/blacklist-amdgpu.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict local user access to systems with AMD GPUs
- Monitor system logs for kernel panic or crash events related to GPU operations
🔍 How to Verify
Check if Vulnerable:
Check if the system has AMD GPU hardware and the amdgpu driver loaded: 'lspci | grep -i amd' and 'lsmod | grep amdgpu'. Check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify the kernel contains the fix commit: 'uname -r' and check kernel source or changelog for commit 3e3fcd29b505cebed659311337ea03b7698767fc📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- System crash reports
- GPU driver error messages
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "NULL pointer dereference") AND "amdgpu"