CVE-2025-23132
📋 TL;DR
This CVE describes a race condition vulnerability in the Linux kernel's F2FS filesystem quota handling. The issue occurs when checkpoint operations race with remount operations, triggering a kernel warning that could potentially lead to system instability or denial of service. This affects Linux systems using the F2FS filesystem with quota support enabled.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
System crash or kernel panic leading to denial of service, potentially causing data corruption in F2FS filesystems.
Likely Case
Kernel warning messages in system logs and temporary system instability during concurrent filesystem operations.
If Mitigated
Minor performance impact during filesystem operations with proper locking mechanisms.
🎯 Exploit Status
Exploitation requires local access and precise timing to trigger the race condition. No known weaponized exploits exist.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel commits d7acf0a6c87aa282c86a36dbaa2f92fda88c5884 and eb85c2410d6f581e957cd03a644ff6ddbe592af9
Vendor Advisory: https://git.kernel.org/stable/c/d7acf0a6c87aa282c86a36dbaa2f92fda88c5884
Restart Required: Yes
Instructions:
1. Update to a kernel version containing the fix commits. 2. Check your distribution's security advisories for backported patches. 3. Reboot the system after kernel update.
🔧 Temporary Workarounds
Disable F2FS quota support
linuxDisable quota support on F2FS filesystems if not required
tune2fs -Q ^usrquota,^grpquota /dev/device
mount -o remount,noquota /mountpoint
Avoid concurrent operations
linuxAvoid performing checkpoint and remount operations simultaneously
🧯 If You Can't Patch
- Monitor system logs for the specific warning messages and investigate any F2FS-related instability
- Consider migrating critical data from F2FS filesystems to alternative filesystems if possible
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if F2FS with quota is in use. Look for the specific warning in dmesg: 'WARNING: CPU: ... at fs/quota/dquot.c:691 dquot_writeback_dquots'Check Version:
uname -rVerify Fix Applied:
Check that kernel version includes the fix commits or verify the warning no longer appears during concurrent F2FS operations📡 Detection & Monitoring
Log Indicators:
- Kernel warning messages containing 'dquot_writeback_dquots' and the specific call trace
- F2FS filesystem error messages during checkpoint operations
Network Indicators:
- None - this is a local filesystem vulnerability
SIEM Query:
source="kernel" AND "dquot_writeback_dquots" AND "WARNING"