CVE-2025-38726
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's ftgmac100 network driver. The flaw occurs when the driver attempts to unregister a fixed PHY after disconnecting it, potentially causing a kernel panic or system crash. This affects systems using the ftgmac100 driver, particularly those with specific network hardware configurations.
💻 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 →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 requiring physical access to reboot the affected system.
Likely Case
System instability or crash when network interface operations trigger the vulnerable code path, resulting in temporary denial of service.
If Mitigated
Minor system instability that may require manual intervention to recover network functionality.
🎯 Exploit Status
Exploitation requires triggering specific network driver operations; likely requires local access or ability to manipulate network interface states.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 44bcd397ad9cd1a6b25fabb7f5edbee4fb0cfc2e or later
Vendor Advisory: https://git.kernel.org/stable/c/44bcd397ad9cd1a6b25fabb7f5edbee4fb0cfc2e
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 ftgmac100 driver
LinuxBlacklist or disable the vulnerable driver if not required
echo 'blacklist ftgmac100' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Avoid using fixed PHY configurations with ftgmac100 driver
- Implement network segmentation to limit exposure to potential triggers
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if ftgmac100 driver is loaded: 'lsmod | grep ftgmac100' and 'uname -r'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is patched and driver loads without errors in system logs📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference errors in dmesg
- Network interface failure logs
Network Indicators:
- Sudden loss of network connectivity on affected interfaces
SIEM Query:
source="kernel" AND ("NULL pointer" OR "ftgmac100" OR "kernel panic")