CVE-2024-47689
📋 TL;DR
A race condition vulnerability in the Linux kernel's F2FS filesystem can cause system crashes or kernel panics when handling critical errors. This affects Linux systems using the F2FS filesystem with the errors=remount-ro mount option. The vulnerability occurs when the filesystem incorrectly sets the read-only flag without proper synchronization during error handling.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
System crash or kernel panic leading to denial of service, potentially causing data corruption or system instability.
Likely Case
System crash or kernel panic when F2FS encounters critical errors, resulting in temporary denial of service until system reboot.
If Mitigated
Minimal impact if systems are not using F2FS filesystem or have patched kernels.
🎯 Exploit Status
Exploitation requires triggering specific race conditions during F2FS error handling, which is complex and requires local access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commits 1f63f405c1a1a64b9c310388aad7055fb86b245c, 649ec8b30df113042588bd3d3cd4e98bcb1091e0, 930c6ab93492c4b15436524e704950b364b2930c, or de43021c72993877a8f86f9fddfa0687609da5a4
Vendor Advisory: https://git.kernel.org/stable/c/1f63f405c1a1a64b9c310388aad7055fb86b245c
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Avoid F2FS with errors=remount-ro
linuxDo not use F2FS filesystem with errors=remount-ro mount option
# Check current mount options: mount | grep f2fs
# Modify /etc/fstab to remove errors=remount-ro from F2FS entries
Use alternative filesystem
linuxUse ext4 or other filesystems instead of F2FS
# Backup data and reformat partitions with alternative filesystem
🧯 If You Can't Patch
- Avoid using F2FS filesystem with errors=remount-ro mount option
- Implement monitoring for kernel panic/crash events related to F2FS
🔍 How to Verify
Check if Vulnerable:
Check if using F2FS with errors=remount-ro: mount | grep 'type f2fs.*errors=remount-ro'Check Version:
uname -rVerify Fix Applied:
Check kernel version contains fix commits: uname -r and verify with distribution's security advisory📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- RCU synchronization warnings in kernel logs
- F2FS error messages in system logs
Network Indicators:
- None - local filesystem vulnerability
SIEM Query:
source="kernel" AND ("rcu_sync_dtor" OR "f2fs_handle_critical_error" OR "WARNING: CPU:")