CVE-2023-53405
📋 TL;DR
A memory leak vulnerability exists in the Linux kernel's USB gadget driver (gr_udc) due to improper handling of debugfs_lookup() calls. This affects Linux systems using the gr_udc USB gadget functionality, potentially leading to gradual memory exhaustion over time. The vulnerability requires local access to trigger.
💻 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
Continuous exploitation could lead to kernel memory exhaustion, causing system instability, denial of service, or kernel panic.
Likely Case
Gradual memory consumption over time leading to performance degradation and potential system crashes in affected USB gadget configurations.
If Mitigated
Minimal impact with proper memory monitoring and system hardening; memory leak would be slow and detectable.
🎯 Exploit Status
Exploitation requires local access to debugfs interface and knowledge of triggering the vulnerable code path.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 0933eca15f5223b5c2412080c8c3de8758465c78, 30f9ba2396a1130eef7f2d3ee7ee8037b7c25be9, 73f4451368663ad28daa67980c6dd11d83b303eb, be21a66e17ee0ab5f3513b6c86659e60cec5e981
Vendor Advisory: https://git.kernel.org/stable/c/0933eca15f5223b5c2412080c8c3de8758465c78
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify gr_udc driver is not vulnerable by checking kernel version.
🔧 Temporary Workarounds
Disable debugfs access
allPrevent access to debugfs interface to block exploitation vector
umount /sys/kernel/debug
echo 'debugfs /sys/kernel/debug debugfs defaults,noauto 0 0' >> /etc/fstab
Unload gr_udc module
allRemove vulnerable driver if not required
rmmod gr_udc
echo 'blacklist gr_udc' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Implement strict access controls to debugfs interface
- Monitor system memory usage for unusual patterns and implement alerting
🔍 How to Verify
Check if Vulnerable:
Check if gr_udc module is loaded: lsmod | grep gr_udc AND check kernel version against patched versionsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits and gr_udc module functions without memory leaks in testing📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- Increasing memory usage in kernel space
- System instability logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("oom" OR "out of memory" OR "panic") AND process="gr_udc"