CVE-2023-53278
📋 TL;DR
A memory leak vulnerability exists in the UBIFS (Unsorted Block Image File System) implementation in the Linux kernel. When the ubifs.ko module is loaded, if kset_register() fails during sysfs initialization, allocated memory is not properly freed. This affects Linux systems using UBIFS, typically on embedded devices with flash storage.
💻 Affected Systems
- Linux Kernel with UBIFS support
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Sustained memory exhaustion leading to kernel OOM (Out of Memory) conditions, system instability, or denial of service through repeated module loading/unloading.
Likely Case
Gradual memory consumption over time if the module is frequently loaded/unloaded, potentially causing performance degradation.
If Mitigated
Minimal impact in most production environments where kernel modules are loaded once at boot and not frequently reloaded.
🎯 Exploit Status
Exploitation requires local access and CAP_SYS_MODULE capability to load/unload kernel modules. The vulnerability is a memory leak rather than a code execution flaw.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits: 1c5fdf2d4647219d2267ccb08c7f2c7095bf3450, 203a55f04f66eea1a1ca7e5a302a7f5c99c62327, d42c2b18c42da7378e67b6414aafe93b65de89d1
Vendor Advisory: https://git.kernel.org/stable/c/1c5fdf2d4647219d2267ccb08c7f2c7095bf3450
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. For embedded systems: rebuild kernel with patches from stable tree. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable UBIFS module loading
LinuxPrevent loading of vulnerable ubifs.ko module if not required
echo 'install ubifs /bin/false' >> /etc/modprobe.d/disable-ubifs.conf
rmmod ubifs 2>/dev/null || true
🧯 If You Can't Patch
- Restrict module loading to authorized users only via kernel.modules_disabled sysctl or capabilities
- Monitor system memory usage for unusual growth patterns
🔍 How to Verify
Check if Vulnerable:
Check if UBIFS module is loaded: lsmod | grep ubifs. If loaded, check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits or is newer than patched versions. Check with: uname -r and compare with distribution security advisories.📡 Detection & Monitoring
Log Indicators:
- Kernel OOM messages in dmesg
- Repeated 'ubifs: loading out-of-tree module taints kernel' messages
- Memory exhaustion alerts in system logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
Process where (command_line contains "insmod ubifs" or command_line contains "modprobe ubifs")