CVE-2025-38411
📋 TL;DR
This CVE describes a double-free vulnerability in the Linux kernel's netfs subsystem where a request reference count is incorrectly decremented twice. This can lead to use-after-free conditions, potentially causing kernel crashes or privilege escalation. All Linux systems using affected kernel versions with netfs functionality are vulnerable.
💻 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
Kernel panic leading to system crash, or privilege escalation allowing attackers to gain root access and execute arbitrary code.
Likely Case
System instability, kernel crashes, or denial of service affecting system availability.
If Mitigated
Limited impact if systems are properly segmented and have minimal network filesystem usage.
🎯 Exploit Status
Exploitation requires triggering specific netfs request conditions; likely requires local access or ability to interact with network filesystems.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check specific kernel versions containing commits 9df7b5ebead649b00bf9a53a798e4bf83a1318fd and d18facba5a5795ad44b2a00a052e3db2fa77ab12
Vendor Advisory: https://git.kernel.org/stable/c/9df7b5ebead649b00bf9a53a798e4bf83a1318fd
Restart Required: Yes
Instructions:
1. Identify current kernel version. 2. Check if patches are available for your distribution. 3. Update kernel package using distribution's package manager. 4. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable netfs functionality
linuxRemove or disable network filesystem modules if not required
modprobe -r <netfs_module>
echo 'blacklist <netfs_module>' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict user access to systems using network filesystems
- Implement strict process isolation and limit kernel module loading
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from kernel git repositoryCheck Version:
uname -rVerify Fix Applied:
Verify kernel version after update matches patched version containing the fix commits📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- OOPs (kernel crashes)
- netfs-related error messages in dmesg
Network Indicators:
- Unusual network filesystem activity patterns
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "netfs")