CVE-2025-39734 – This CVE addresses a deadlock vulnerability in ... (How to Fix)

📋 TL;DR

This CVE addresses a deadlock vulnerability in the Linux kernel's NTFS3 filesystem driver. The issue occurs when the driver attempts to acquire inode locks unconditionally, potentially causing system hangs or crashes. Systems using the NTFS3 driver with affected kernel versions are vulnerable.

💻 Affected Systems

Products:

Linux kernel with NTFS3 driver

Versions: Kernel versions containing commit 69505fe98f198ee813898cbcaf6770949636430b up to the revert

Operating Systems: Linux distributions with affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using the NTFS3 filesystem driver (not NTFS-3G userspace driver)

📦 What is this software?

Debian Linux by Debian

View all CVEs affecting Debian Linux →

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...

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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

Complete system deadlock requiring hard reboot, potential data corruption or loss in NTFS filesystems

🟠

Likely Case

System hangs or crashes when accessing NTFS filesystems, leading to denial of service

🟢

If Mitigated

Minor performance impact with conditional locking restored

🌐 Internet-Facing: LOW - Requires local filesystem access

🏢 Internal Only: MEDIUM - Local users or processes accessing NTFS filesystems could trigger deadlock

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires triggering specific NTFS filesystem operations; discovered via syzbot fuzzing

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions with revert commit 1903a6c1f2818154f6bc87bceaaecafa92b6ac5c or later

Vendor Advisory: https://git.kernel.org/stable/c/1903a6c1f2818154f6bc87bceaaecafa92b6ac5c

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the revert commit
2. Reboot system to load patched kernel
3. Verify kernel version after reboot

🔧 Temporary Workarounds

Disable NTFS3 driver

all

Prevent loading of the vulnerable NTFS3 kernel module

echo 'blacklist ntfs3' >> /etc/modprobe.d/blacklist-ntfs3.conf
rmmod ntfs3

Use NTFS-3G userspace driver

all

Switch to the FUSE-based NTFS-3G driver instead of kernel NTFS3

apt-get install ntfs-3g
yum install ntfs-3g

🧯 If You Can't Patch

Avoid mounting NTFS filesystems using the NTFS3 driver
Monitor system logs for deadlock indicators and have reboot procedures ready

🔍 How to Verify

Check if Vulnerable:

Check if current kernel contains the problematic commit: 'git log --oneline | grep 69505fe98f198ee813898cbcaf6770949636430b'

Check Version:

uname -r

Verify Fix Applied:

Verify the revert commit is present: 'git log --oneline | grep 1903a6c1f2818154f6bc87bceaaecafa92b6ac5c'

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
System hang detection in monitoring tools
NTFS3 driver error messages in dmesg

Network Indicators:

None - local filesystem issue

SIEM Query:

source="kernel" AND ("deadlock" OR "hung task" OR "ntfs3")

📊 Metadata

CVE ID: CVE-2025-39734

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Score: 0.01% exploit probability (1.2th percentile)

Published: September 7, 2025

Last Updated: January 12, 2026

🔗 References

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