CVE-2025-39693
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the AMD display driver component of the Linux kernel. If exploited, it could cause a kernel panic or system crash, affecting systems running vulnerable Linux kernel versions with AMD graphics hardware. The vulnerability occurs when the kernel fails to properly validate return values from display connector state functions.
💻 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 →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 system instability.
Likely Case
System crash or kernel panic when specific display operations are performed, resulting in temporary denial of service.
If Mitigated
System remains stable as the NULL check prevents dereferencing invalid pointers.
🎯 Exploit Status
Exploitation requires local access and ability to trigger specific display operations. The NULL pointer condition is described as 'unlikely' in the commit message.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commit 1e5e8d672fec9f2ab352be121be971877bff2af9 or backported fixes
Vendor Advisory: https://git.kernel.org/stable/c/07b93a5704b0b72002f0c4bd1076214af67dc661
Restart Required: Yes
Instructions:
1. Update Linux kernel to a version containing the fix. 2. Check with your distribution vendor for specific patched kernel packages. 3. Reboot the system to load the new kernel.
🔧 Temporary Workarounds
Disable AMD display driver
LinuxPrevent loading of the vulnerable AMD display driver module
echo 'blacklist amdgpu' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict local user access to minimize attack surface
- Implement strict privilege separation and limit users who can perform display operations
🔍 How to Verify
Check if Vulnerable:
Check if your kernel version is before the fix commit: 'uname -r' and compare with distribution security advisoriesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version after update and check that the AMD display driver loads without issues📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- NULL pointer dereference errors in kernel logs
- System crash/reboot events
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "kernel panic" OR "Oops") AND process="amdgpu"🔗 References
- https://git.kernel.org/stable/c/07b93a5704b0b72002f0c4bd1076214af67dc661
- https://git.kernel.org/stable/c/0c1a486cbe6f9cb194e3c4a8ade4af2a642ba165
- https://git.kernel.org/stable/c/36a6b43573d152736eaf2557fe60580dd73e9350
- https://git.kernel.org/stable/c/6f860abff89417c0354b6ee5bbca188a233c5762
- https://git.kernel.org/stable/c/9c92d12b5cb9d9d88c12ae71794d3a7382fcdec0
- https://git.kernel.org/stable/c/f653dd30839eb4f573a7539e90b8a58ff9bedf2f
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
