CVE-2025-22055
📋 TL;DR
A heap out-of-bounds read vulnerability exists in the Linux kernel's GENEVE (Generic Network Virtualization Encapsulation) option parsing due to integer overflow. Attackers can craft malicious 128-byte GENEVE options to bypass length checks and read kernel memory. This affects all Linux systems using GENEVE tunneling.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory disclosure leading to information leakage, potential privilege escalation, or system crash/DoS.
Likely Case
Information disclosure of kernel memory contents, potentially exposing sensitive data or system state.
If Mitigated
Limited impact if systems don't use GENEVE tunneling or have strict network controls.
🎯 Exploit Status
Exploit requires network access to GENEVE interfaces and ability to send crafted packets. The crash log shows a working proof-of-concept.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 21748669c5825761cbbf47cbeeb01387ddccc8cb and related fixes
Vendor Advisory: https://git.kernel.org/stable/c/21748669c5825761cbbf47cbeeb01387ddccc8cb
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. For custom kernels, apply the fix commits. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable GENEVE tunneling
linuxRemove or disable GENEVE tunnel interfaces if not required
ip link delete geneve0
modprobe -r geneve
Network filtering
linuxBlock GENEVE traffic (UDP port 6081) at network boundaries
iptables -A INPUT -p udp --dport 6081 -j DROP
🧯 If You Can't Patch
- Disable all GENEVE tunnel interfaces and modules
- Implement strict network segmentation to isolate GENEVE traffic
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if GENEVE module is loaded: uname -r && lsmod | grep geneveCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is after fix commits and test with known exploit PoC📡 Detection & Monitoring
Log Indicators:
- KASAN reports of slab-out-of-bounds reads
- Kernel crashes in geneve_opt parsing functions
Network Indicators:
- Unusual GENEVE traffic patterns
- Malformed GENEVE option packets of exactly 128 bytes
SIEM Query:
source="kernel" AND ("KASAN" OR "slab-out-of-bounds" OR "geneve_opt")🔗 References
- https://git.kernel.org/stable/c/21748669c5825761cbbf47cbeeb01387ddccc8cb
- https://git.kernel.org/stable/c/2952776c69a1a551649ed770bf22e3f691f6ec65
- https://git.kernel.org/stable/c/4d606069bdd3c76f8ab1f06796c97ef7f4746807
- https://git.kernel.org/stable/c/5a2976cc4d9c36ff58a0f10e35ce4283cbaa9c0e
- https://git.kernel.org/stable/c/738ae5712215fe9181587d582b23333f02c62ca6
- https://git.kernel.org/stable/c/a2cb85f989e2074e2f392e00188c438cab3de088
- https://git.kernel.org/stable/c/b27055a08ad4b415dcf15b63034f9cb236f7fb40
- https://git.kernel.org/stable/c/b4513ad0f391871d3feee8ddf535609a3aabeeac
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
