CVE-2025-71148
📋 TL;DR
A memory leak vulnerability in the Linux kernel's handshake subsystem occurs when socket submission fails, preventing the original socket destructor from running. This affects Linux systems using the handshake functionality, potentially leading to resource exhaustion over time. Kernel-level access is required to trigger this issue.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Sustained exploitation could lead to kernel memory exhaustion, causing system instability, denial of service, or crashes.
Likely Case
Local attackers with kernel access could cause gradual memory leaks, potentially degrading system performance over time.
If Mitigated
With proper access controls and monitoring, impact is limited to potential performance degradation from memory leaks.
🎯 Exploit Status
Requires local access and ability to trigger handshake submission failures; not trivial to exploit
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits: 6af2a01d65f89e73c1cbb9267f8880d83a88cee4, 7b82a1d6ae869533d8bdb0282a3a78faed8e63dd, b225325be7b247c7268e65eea6090db1fc786d1f, cd8cf2be3717137554744233fda051ffc09d1d44
Vendor Advisory: https://git.kernel.org/stable/c/
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version 2. Reboot system 3. Verify kernel version matches patched commit
🔧 Temporary Workarounds
Disable handshake functionality
linuxRemove or disable handshake module if not required
modprobe -r handshake
echo 'blacklist handshake' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict local user access to prevent kernel-level operations
- Implement memory monitoring and alerting for unusual kernel memory usage
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if handshake module is loaded: lsmod | grep handshakeCheck Version:
uname -rVerify Fix Applied:
Verify kernel includes fix commits: git log --oneline | grep -E '6af2a01d|7b82a1d6|b225325b|cd8cf2be'📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- Memory allocation failures in dmesg
- System performance degradation logs
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
source="kernel" AND ("handshake" OR "sk_destruct" OR "memory leak")