CVE-2024-56744
📋 TL;DR
This CVE describes a potential deadlock vulnerability in the Linux kernel's F2FS filesystem. The issue occurs in the f2fs_record_stop_reason() function when acquiring locks in a specific order that can create a circular dependency, potentially causing system hangs or crashes. This affects systems using the F2FS filesystem with vulnerable kernel versions.
💻 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
System deadlock leading to kernel panic, filesystem corruption, or complete system unavailability requiring hard reboot.
Likely Case
System hangs or performance degradation when specific F2FS operations trigger the deadlock condition during filesystem maintenance or error handling.
If Mitigated
Minor performance impact or no noticeable effect if the deadlock condition isn't triggered.
🎯 Exploit Status
This is a race condition/deadlock vulnerability that requires specific timing and conditions to trigger. Exploitation would likely require local access and ability to perform specific F2FS operations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 1539a088b108996bcdaddb7775070b5163b14233, 801092a2c9c251ef6a8678fcb8fcc1220474a697, ecf4e6782b01fd578b565b3dd2be7bb0ac91082e, f10a890308a7cd8794e21f646f09827c6cb4bf5d
Vendor Advisory: https://git.kernel.org/stable/c/1539a088b108996bcdaddb7775070b5163b14233
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check with your distribution vendor for specific patched kernel versions. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable F2FS filesystem
linuxAvoid using F2FS filesystem on affected systems
# Do not format partitions with F2FS
# Use alternative filesystems like ext4, xfs, or btrfs
Kernel module blacklist
linuxPrevent F2FS module from loading
echo 'blacklist f2fs' >> /etc/modprobe.d/blacklist-f2fs.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Monitor system logs for deadlock warnings or kernel panics
- Implement robust monitoring and alerting for system availability
- Ensure proper backups of critical data on F2FS partitions
- Consider migrating critical data to alternative filesystems
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if F2FS is in use: uname -r && lsmod | grep f2fs && mount | grep f2fsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits: git log --oneline | grep -E '1539a088b108996bcdaddb7775070b5163b14233|801092a2c9c251ef6a8678fcb8fcc1220474a697|ecf4e6782b01fd578b565b3dd2be7bb0ac91082e|f10a890308a7cd8794e21f646f09827c6cb4bf5d'📡 Detection & Monitoring
Log Indicators:
- Kernel messages about circular locking dependency
- WARNING: possible circular locking dependency detected
- System hangs or unresponsiveness
- F2FS error messages in dmesg
Network Indicators:
- None - this is a local filesystem issue
SIEM Query:
source="kernel" AND ("circular locking" OR "deadlock" OR "f2fs_record_stop_reason")