CVE-2025-39778
📋 TL;DR
This CVE describes an out-of-bounds read vulnerability in the Linux kernel's NVMe over Fabrics (NVMe-oF) subsystem. The vulnerability allows reading beyond allocated memory boundaries in the nvmet_ctrl_state_show() function, potentially exposing kernel memory contents. Systems running affected Linux kernel versions with NVMe-oF enabled 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory disclosure leading to information leaks, potential privilege escalation if combined with other vulnerabilities, or system crashes/instability.
Likely Case
Information disclosure of kernel memory contents, potentially exposing sensitive data or system state information.
If Mitigated
Limited impact due to the specific nature of the out-of-bounds read and typical NVMe-oF deployment scenarios.
🎯 Exploit Status
Exploitation requires access to NVMe-oF subsystem and specific conditions; primarily an information disclosure vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing fixes from provided git commits
Vendor Advisory: https://git.kernel.org/stable/c/0cc0efc58d6c741b2868d4af24874d7fec28a575
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Reboot system. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable NVMe-oF subsystem
linuxDisable the NVMe over Fabrics subsystem if not required
modprobe -r nvmet
echo 'blacklist nvmet' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Disable NVMe-oF subsystem if not essential for operations
- Implement network segmentation to isolate NVMe-oF traffic
🔍 How to Verify
Check if Vulnerable:
Check if NVMe-oF module is loaded: lsmod | grep nvmetCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to include the fix commits📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- UBSAN warnings related to out-of-bounds access
- System instability after NVMe-oF operations
Network Indicators:
- Unusual NVMe-oF traffic patterns
- Multiple connection attempts to NVMe-oF ports
SIEM Query:
source="kernel" AND ("UBSAN" OR "out-of-bounds" OR "nvmet")