CVE-2023-53408
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's blktrace subsystem. When debugfs_lookup() is called without proper cleanup, kernel memory gradually leaks over time. This affects all Linux systems using the affected kernel versions with blktrace functionality.
💻 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.
Likely Case
Gradual memory consumption over time leading to performance degradation and potential system instability.
If Mitigated
Minimal impact with proper monitoring and memory limits in place.
🎯 Exploit Status
Exploitation requires local access and ability to trigger blktrace operations. Memory leak occurs gradually over time rather than immediate impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with fixes (see references)
Vendor Advisory: https://git.kernel.org/stable/c/3036f5f5ae5210797d95446795df01c1249af9ad
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable blktrace
allPrevent use of blktrace functionality to avoid triggering the vulnerability
echo 0 > /sys/kernel/debug/tracing/events/block/enable
rmmod blktrace
🧯 If You Can't Patch
- Monitor kernel memory usage closely for unusual increases
- Restrict access to blktrace functionality to trusted users only
🔍 How to Verify
Check if Vulnerable:
Check kernel version against patched versions in references. Vulnerable if using unpatched kernel with blktrace support.Check Version:
uname -rVerify Fix Applied:
Verify kernel version matches patched version and monitor for memory leaks during blktrace operations.📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- System instability logs
- Memory pressure warnings
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for: kernel: "Out of memory" OR "oom-killer" OR memory pressure warnings