CVE-2025-21652
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's ipvlan network driver allows attackers to potentially crash the kernel or execute arbitrary code. This affects Linux systems using ipvlan interfaces, particularly in containerized environments. The vulnerability occurs when the kernel attempts to access a freed network device pointer during link state updates.
💻 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 →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 potential arbitrary code execution with kernel privileges resulting in complete system compromise.
Likely Case
Kernel crash or system instability requiring reboot, potentially causing denial of service in affected systems.
If Mitigated
Limited impact if ipvlan interfaces are not in use or if systems are patched before exploitation attempts.
🎯 Exploit Status
Requires local access to create ipvlan interfaces and trigger the race condition. Exploitation timing is challenging but possible in container environments.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel stable releases containing commits: 52a24538d569f48e79d1a169a5d359d384152950, ba9f7c16ec879c83bb4f80406773a911aace8267, cb358ff94154774d031159b018adf45e17673941
Vendor Advisory: https://git.kernel.org/stable/c/52a24538d569f48e79d1a169a5d359d384152950
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. For custom kernels: apply the git commits listed in references. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable ipvlan interfaces
allPrevent creation of ipvlan network interfaces to eliminate attack surface
# Check for existing ipvlan interfaces
ip link show type ipvlan
# Remove any existing ipvlan interfaces
ip link delete <interface_name>
# Prevent ipvlan module loading
echo 'blacklist ipvlan' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Avoid using ipvlan networking in container configurations
- Implement strict container isolation and limit container capabilities to prevent interface creation
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if ipvlan interfaces exist: 'uname -r' and 'ip link show type ipvlan'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check git commit history includes the fix commits📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- KASAN use-after-free reports in dmesg
- System crash/reboot events
Network Indicators:
- Unexpected network interface disappearance
- Container networking failures
SIEM Query:
source="kernel" AND ("KASAN" OR "use-after-free" OR "ipvlan" OR "panic")