CVE-2025-37945
📋 TL;DR
A Linux kernel vulnerability in the network PHY subsystem allows improper handling of PHY state machine during suspend/resume operations when using phylink with MDIO-bus-managed PHY power management. This affects systems using specific network drivers that don't properly manage PHY power states, potentially causing system instability or denial of service. The vulnerability primarily impacts Linux systems with affected network hardware drivers.
💻 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 →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
System crash or kernel panic during suspend/resume cycles, leading to denial of service and potential data loss.
Likely Case
Warning messages in kernel logs and potential network connectivity issues during system suspend/resume operations.
If Mitigated
Minor performance impact during power state transitions with proper kernel patching.
🎯 Exploit Status
Exploitation requires specific hardware/driver combinations and system suspend/resume operations. This appears to be a stability bug rather than a security vulnerability with traditional exploitation vectors.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel commits: 043aa41c43f8, 54e5d00a8de6, a6ed6f8ec81b, bd4037d51d3f, fc75ea20ffb4
Vendor Advisory: https://git.kernel.org/stable/c/043aa41c43f8cb9cce75367ea07895ce68b5abb0
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check with your distribution for backported patches. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable affected network interfaces
linuxTemporarily disable network interfaces using affected drivers to prevent suspend/resume issues
sudo ip link set <interface> down
Disable system suspend
linuxPrevent system from entering suspend states where the vulnerability triggers
sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target
🧯 If You Can't Patch
- Monitor kernel logs for PHY state warnings during suspend/resume cycles
- Avoid using suspend/resume functionality on affected systems
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if using affected network drivers. Look for kernel warnings about PHY state during suspend/resume.Check Version:
uname -rVerify Fix Applied:
Check kernel version contains fix commits. Test suspend/resume cycles while monitoring dmesg for PHY-related warnings.📡 Detection & Monitoring
Log Indicators:
- Kernel warnings about PHY state not being HALTED/READY/UP during resume
- Messages containing 'mdio_bus_phy_resume' with WARN_ON triggers
Network Indicators:
- Network connectivity loss after system resume
SIEM Query:
source="kernel" AND ("PHY_HALTED" OR "PHY_READY" OR "PHY_UP" OR "mdio_bus_phy_resume")🔗 References
- https://git.kernel.org/stable/c/043aa41c43f8cb9cce75367ea07895ce68b5abb0
- https://git.kernel.org/stable/c/54e5d00a8de6c13f6c01a94ed48025e882cd15f7
- https://git.kernel.org/stable/c/a6ed6f8ec81b8ca7100dcd9e62bdbc0dff1b2259
- https://git.kernel.org/stable/c/bd4037d51d3f6667636a1383e78e48a5b7b60755
- https://git.kernel.org/stable/c/fc75ea20ffb452652f0d4033f38fe88d7cfdae35
