CVE-2023-52737
📋 TL;DR
A race condition vulnerability in the Linux kernel's Btrfs filesystem can cause a deadlock when the fiemap ioctl operation runs concurrently with fsync. This affects Linux systems using Btrfs filesystem and can lead to denial of service by freezing affected processes.
💻 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 →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 →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 becomes unresponsive due to kernel deadlock, requiring reboot to restore functionality.
Likely Case
Processes performing fiemap operations hang indefinitely, causing application failures and degraded system performance.
If Mitigated
Minimal impact if systems are patched or don't use Btrfs filesystem.
🎯 Exploit Status
Requires local access and ability to trigger concurrent fiemap and fsync operations on Btrfs filesystem.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 519b7e13b5ae8dd38da1e52275705343be6bb508 and d8c594da79bc0244e610a70594e824a401802be1
Vendor Advisory: https://git.kernel.org/stable/c/519b7e13b5ae8dd38da1e52275705343be6bb508
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel.
🔧 Temporary Workarounds
Avoid Btrfs filesystem
linuxUse alternative filesystems like ext4 or xfs for critical systems
Restrict fiemap usage
linuxLimit applications that use fiemap ioctl on Btrfs filesystems
🧯 If You Can't Patch
- Monitor systems for hung processes related to Btrfs operations
- Implement process monitoring and automatic restart for critical services
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if Btrfs is in use: uname -r && cat /proc/filesystems | grep btrfsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or is newer than vulnerable versions📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing hung tasks or deadlock warnings
- Processes stuck in D state (uninterruptible sleep)
SIEM Query:
source="kernel" AND ("hung task" OR "deadlock" OR "blocked for more than")