CVE-2023-53390
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's device driver subsystem. When debugfs_lookup() is called without proper cleanup, kernel memory is not released, leading to gradual resource exhaustion. This affects all Linux systems using the affected kernel versions with debugfs enabled.
💻 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
Sustained exploitation could lead to kernel memory exhaustion, causing system instability, crashes, or denial of service through resource depletion.
Likely Case
Gradual memory leak over time leading to performance degradation and potential system instability requiring reboots.
If Mitigated
Minimal impact with proper monitoring and memory limits in place; system remains functional but may require occasional maintenance.
🎯 Exploit Status
Exploitation requires local access and ability to interact with debugfs; not a privilege escalation vulnerability but can cause denial of service.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing the fix commits: 36c893d3a759ae7c91ee7d4871ebfc7504f08c40, 5a7a9efdb193d3c8a35821548a8e99612c358828, 7f1e53f88e8babf293ec052b70aa9d2a3554360c, 8e47e2bf78812adbd73c45c941d3c51add30b58d
Vendor Advisory: https://git.kernel.org/stable/c/
Restart Required: Yes
Instructions:
1. Update to a kernel version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable debugfs access
allPrevent access to debugfs filesystem to block potential exploitation vectors
umount /sys/kernel/debug
echo 'debugfs /sys/kernel/debug debugfs noauto 0 0' >> /etc/fstab
Restrict debugfs permissions
allLimit access to debugfs to privileged users only
chmod 700 /sys/kernel/debug
chown root:root /sys/kernel/debug
🧯 If You Can't Patch
- Implement strict access controls to /sys/kernel/debug directory
- Monitor system memory usage and implement alerts for abnormal memory consumption patterns
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if it contains the vulnerable code by examining kernel source or distribution security advisoriesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or check with distribution's security update verification tools📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- System memory exhaustion warnings in syslog
- High memory usage by kernel processes
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("out of memory" OR "oom-killer" OR "memory exhaustion")