CVE-2023-53272
📋 TL;DR
This CVE describes a shift-out-of-bounds vulnerability in the Linux kernel's ENA (Elastic Network Adapter) driver exponential backoff function. When network adapters reset, the delay calculation can overflow, potentially causing undefined behavior or kernel panics. This affects Linux systems using Amazon ENA network adapters, particularly in cloud environments like AWS EC2 instances.
💻 Affected Systems
- Linux kernel with ENA driver
📦 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 and denial of service, potentially disrupting critical network services and causing system instability.
Likely Case
System instability during network adapter resets, with potential for kernel warnings/errors in logs and occasional service disruption.
If Mitigated
Minor performance impact during network resets with proper error handling and no system crashes.
🎯 Exploit Status
Exploitation requires triggering network adapter resets under specific timing conditions. The vulnerability was discovered through UBSAN (Undefined Behavior Sanitizer) detection rather than active exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in kernel commits referenced in CVE (e.g., 0939c264729d4a081ff88efce2ffdf85dc5331e0)
Vendor Advisory: https://git.kernel.org/stable/c/0939c264729d4a081ff88efce2ffdf85dc5331e0
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. For cloud instances, update to latest AMI/instance image with patched kernel. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable UBSAN detection
linuxDisable Undefined Behavior Sanitizer to prevent panic on detection, though this doesn't fix the underlying issue
echo 0 > /proc/sys/kernel/panic_on_ubsan
Limit network resets
linuxMonitor and limit conditions that trigger ENA adapter resets
🧯 If You Can't Patch
- Monitor system logs for UBSAN warnings related to ENA driver
- Implement high availability configurations to minimize impact of potential crashes
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if ENA driver is loaded: lsmod | grep ena && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated beyond vulnerable commits and check for absence of UBSAN warnings in dmesg📡 Detection & Monitoring
Log Indicators:
- UBSAN: shift-out-of-bounds in ena_com.c
- kernel panic messages
- ENA driver reset failures
Network Indicators:
- Unusual network adapter reset patterns
- Increased network timeouts on ENA interfaces
SIEM Query:
source="kernel" AND ("UBSAN" AND "shift-out-of-bounds" AND "ena_com.c") OR ("ENA" AND "reset" AND "panic")🔗 References
- https://git.kernel.org/stable/c/0939c264729d4a081ff88efce2ffdf85dc5331e0
- https://git.kernel.org/stable/c/1e760b2d18bf129b3da052c2946c02758e97d15e
- https://git.kernel.org/stable/c/1e9cb763e9bacf0c932aa948f50dcfca6f519a26
- https://git.kernel.org/stable/c/3e36cc94d6e60a27f27498adf1c71eeba769ab33
- https://git.kernel.org/stable/c/90947ebf8794e3c229fb2e16e37f1bfea6877f14
