CVE-2023-53409
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's component framework when using debugfs_lookup() without proper cleanup. The vulnerability allows attackers to gradually exhaust kernel memory over time, potentially leading to system instability or denial of service. All Linux systems using affected kernel versions 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
System crashes or becomes unresponsive due to kernel memory exhaustion, leading to complete denial of service and potential data loss.
Likely Case
Gradual performance degradation and system instability over time as kernel memory becomes fragmented and depleted.
If Mitigated
Minimal impact with proper monitoring and memory limits in place, though system may still experience performance issues.
🎯 Exploit Status
Exploitation requires local access to trigger the vulnerable debugfs_lookup() calls repeatedly
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 09709a49283f79184c998d6dafcc01590e4d654d, 79ac2b01e033181e21cc84216ace1f4160eb8950, 8deb87b1e810dd558371e88ffd44339fbef27870, bf0fd01c7cc1061fb2cfda3e2044371642108e6c
Vendor Advisory: https://git.kernel.org/stable/c/
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 debugfs
allPrevent exploitation by disabling debugfs filesystem
mount -t debugfs none /sys/kernel/debug -o remount,ro
echo 'debugfs /sys/kernel/debug debugfs defaults,ro 0 0' >> /etc/fstab
🧯 If You Can't Patch
- Implement strict access controls to limit who can access debugfs interfaces
- Monitor kernel memory usage and implement alerts for abnormal memory consumption patterns
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from kernel git repositoryCheck Version:
uname -rVerify Fix Applied:
Verify kernel version after update and check that debugfs_lookup_and_remove() is used instead of debugfs_lookup() in component driver code📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- Memory allocation failures in kernel logs
- System performance degradation logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("oom-killer" OR "memory allocation failure" OR "slab allocation")