CVE-2025-23137
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's AMD CPU frequency scaling driver (amd-pstate). If exploited, it could cause a kernel panic or system crash on systems using affected AMD processors. The vulnerability affects Linux systems with AMD CPUs that use the amd-pstate driver.
💻 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 →⚠️ 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 requiring reboot, resulting in temporary service unavailability.
If Mitigated
Minimal impact if proper kernel hardening and privilege separation are in place, though system stability could still be affected.
🎯 Exploit Status
Exploitation requires local access and ability to trigger the amd-pstate update function with a NULL policy pointer. The vulnerability is a NULL pointer dereference which typically requires specific conditions to trigger.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing the fix commits: 426db24d4db2e4f0d6720aeb7795eafcb9e82640, 82b6dfff0d6000b14b271f74e43d672d81fb390e, b99c1c63d88c75a4dc5487c3696cda38697b8d35
Vendor Advisory: https://git.kernel.org/stable/c/426db24d4db2e4f0d6720aeb7795eafcb9e82640
Restart Required: Yes
Instructions:
1. Update to a patched kernel version from your distribution's repositories. 2. Rebuild kernel if using custom kernel. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable amd-pstate driver
linuxSwitch to a different CPU frequency scaling driver like acpi-cpufreq
echo 'GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT amd_pstate=disable"' | sudo tee -a /etc/default/grub
sudo update-grub
sudo reboot
🧯 If You Can't Patch
- Restrict local user access to systems with AMD CPUs using amd-pstate driver
- Implement kernel hardening features like KASLR and strict memory protections
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if amd-pstate driver is loaded: 'uname -r' and 'lsmod | grep amd_pstate'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check dmesg for amd-pstate driver loading without errors📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- NULL pointer dereference errors related to amd_pstate
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "kernel panic") AND "amd_pstate"