CVE-2023-53406
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's USB gadget driver for PXA25x processors. When debugfs_lookup() is called without proper cleanup, kernel memory gradually leaks, potentially leading to system instability. Systems using affected Linux kernel versions with PXA25x USB gadget functionality enabled 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
Sustained exploitation could cause kernel memory exhaustion, leading to system crashes, denial of service, or unpredictable system behavior including potential privilege escalation if combined with other vulnerabilities.
Likely Case
Gradual memory consumption over time causing system performance degradation, instability, or eventual crashes requiring reboots.
If Mitigated
Minimal impact with proper monitoring and memory limits in place; system remains functional but may experience occasional performance issues.
🎯 Exploit Status
Requires local access and ability to trigger USB gadget debugfs operations; memory leak is gradual rather than immediate.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 6236a6d2cdfb710bd8a82c4b179d0a034d0d99cb, 78d9586d8e728be1e360d3d0da7170c791d1d55e, 7a038a681b7df78362d9fc7013e5395a694a9d3a, 8d48a7887dbca22e064c20caf20ae7949019fe9b
Vendor Advisory: https://git.kernel.org/stable/c/
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable USB gadget debugfs
linuxPrevent debugfs operations that trigger the memory leak
echo 0 > /sys/kernel/debug/usb/gadget/pxa25x_udc/enable
mount -o remount,nodebugfs /sys/kernel/debug
🧯 If You Can't Patch
- Disable CONFIG_USB_GADGET_PXA25X kernel module if not needed
- Implement memory monitoring and alerting for kernel memory consumption
🔍 How to Verify
Check if Vulnerable:
Check if kernel has PXA25x USB gadget enabled: lsmod | grep pxa25x_udc && check kernel version against patched commitsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits: git log --oneline | grep -E '6236a6d2cdfb|78d9586d8e72|7a038a681b7d|8d48a7887dbca'📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- Increasing kernel memory usage in /proc/meminfo
- System instability or crash logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("Out of memory" OR "kernel panic" OR "slab allocation failure")