CVE-2026-89625 Linux Kernel HID Sony Driver Use-After-Free Vulnerability – Impact, Detection, and Mitigation

Introduction

CVE-2026-89625 is a use-after-free vulnerability in the Linux kernel’s HID Sony driver that affects systems using Guitar Hero Live (GHL) dongles. This flaw creates a race condition during driver unbinding that can lead to arbitrary code execution or system crashes. If you’re running a Linux kernel prior to the next-20260710 release and use HID gaming peripherals, you should assess your exposure immediately and plan patching accordingly.

What Is CVE-2026-89625?

The Vulnerability Explained

CVE-2026-89625 represents a critical memory safety issue in the Linux kernel’s HID Sony driver. The vulnerability stems from improper synchronization between a periodic timer and USB request block (URB) cleanup during the driver unbinding process. When these components are not properly coordinated, freed memory can be accessed, leading to system instability or potential code execution.

This type of vulnerability is particularly concerning because it operates at the kernel level, where an attacker gaining control can compromise the entire system.

Why the HID Sony Driver Is Affected

The HID Sony driver manages input devices manufactured by Sony, including the Guitar Hero Live wireless dongle. The driver initializes a periodic timer (ghl_magic_poke()) that submits USB requests to maintain device connectivity. The vulnerability exists because the timer cleanup mechanism doesn’t prevent the timer from being re-armed after the associated USB request block has been freed.

Use-After-Free: The Core Issue

A use-after-free vulnerability occurs when a program attempts to access memory that has already been deallocated. In this case:

• Memory is allocated for a USB request block (URB)
• A timer is configured to periodically use this URB
• During driver shutdown, the URB is freed
• The timer can still fire and attempt to use the freed URB
• This results in accessing invalid memory addresses

This is distinct from buffer overflows or other memory corruption issues because the memory was legitimately allocated and used—the problem is the timing of its deallocation.

Which Systems Are at Risk?

Affected Linux Kernel Versions

The vulnerability affects Linux kernel versions prior to the next-20260710 release. Specific version numbers depend on your distribution’s kernel branch. Most affected are:

• Kernel versions from 5.10 through 6.x (prior to the patched release)
• Distributions using unpatched kernel sources from the affected timeline
• Custom kernels compiled without the fix

Check your kernel version with:

uname -r

Hardware Requirements

The vulnerability requires specific hardware to be present or connected:

• Primary trigger: Guitar Hero Live wireless dongle (Sony HID device)
• Secondary exposure: Any Sony HID gaming peripheral using the affected driver
• Connection method: USB connection to the affected system

Systems without these devices may still be vulnerable if the driver is compiled into the kernel, though exploitation would be more difficult.

Deployment Scenarios with Higher Risk

Certain environments face elevated risk:

• Gaming cafes and entertainment venues using GHL equipment
• Educational institutions with music technology labs
• Shared computing environments where users connect personal gaming peripherals
• Systems with automatic driver loading for all HID devices
• Embedded systems running Linux with limited update capabilities

How the Vulnerability Works

The Timer and URB Mechanism

The HID Sony driver implements a “magic poke” mechanism to maintain device connectivity:

1. Initialization (sony_probe()): A periodic timer is armed that fires every few milliseconds
2. Timer callback (ghl_magic_poke()): Submits a USB request block to the device
3. Completion callback (ghl_magic_poke_cb()): Re-arms the timer using mod_timer()

This creates a continuous cycle of USB communication that keeps the device responsive.

The Race Condition During Driver Unbinding

When the driver is unbound (device disconnected or driver unloaded):

Timeline of the race condition:
T1: sony_remove() called
T2: timer_delete_sync() executes (attempts to stop timer)
T3: ghl_magic_poke_cb() fires (timer callback still executing)
T4: mod_timer() re-arms the timer
T5: usb_free_urb() deallocates the URB
T6: Timer fires again
T7: ghl_magic_poke() tries to use freed URB → CRASH or CODE EXECUTION

The critical issue: timer_delete_sync() waits for the current timer callback to complete, but it cannot prevent the callback from re-arming the timer before the URB is freed.

Memory Access After Deallocation

Once the URB is freed, the timer’s next firing attempts to:

• Submit the freed URB to the USB subsystem
• Access memory structures that no longer belong to the driver
• Potentially write to memory now allocated to other kernel components

This creates an exploitable condition where an attacker can influence what happens to the freed memory.

Real-World Attack Scenarios

Remote Code Execution Paths

An attacker could exploit this vulnerability through:

1. Device connection trigger: Connect a malicious USB device that mimics a GHL dongle
2. Race condition exploitation: Time the device disconnection to trigger the use-after-free
3. Memory manipulation: If the freed URB memory is reallocated to attacker-controlled data structures, the timer callback could execute arbitrary code
4. Privilege escalation: Since the vulnerability exists in kernel code, successful exploitation grants kernel-level access

This attack requires either:

• Physical access to connect a USB device, OR
• Ability to trigger driver unbinding remotely (less common)

Denial of Service Exploitation

A simpler attack path involves crashing the system:

1. Connect a GHL dongle (or malicious device)
2. Trigger rapid connect/disconnect cycles
3. Force the race condition to occur
4. Kernel panic when accessing freed memory
5. System becomes unavailable

This requires only the ability to connect/disconnect USB devices.

Practical Attack Requirements

For local exploitation:

• Physical USB port access
• Ability to connect devices
• Knowledge of timing windows (milliseconds)

For remote exploitation:

• Existing code execution on the system
• Ability to trigger driver unbinding
• Less practical in most scenarios

Severity and Risk Assessment

CVSS Scoring and Impact

While an official CVSS score hasn’t been published, the vulnerability characteristics suggest a high severity rating (7.5-9.0 range):

• Attack Vector: Local (requires device connection)
• Attack Complexity: High (race condition timing required)
• Privileges Required: None (can be triggered by unprivileged user)
• User Interaction: None
• Scope: Changed (affects entire system)
• Confidentiality Impact: High (kernel memory access)
• Integrity Impact: High (code execution potential)
• Availability Impact: High (denial of service)

Threat Level for Different Environments

Who Should Prioritize Patching

Immediate priority (patch within 24-48 hours):

• Systems actively using GHL dongles
• Gaming venues and entertainment systems
• Multi-user shared systems
• Systems with physical USB access restrictions

High priority (patch within 1-2 weeks):

• Desktop systems with HID driver compiled in
• Development systems
• Systems with automatic driver loading

Standard priority (patch within monthly cycle):

• Servers without gaming peripherals
• Isolated systems with restricted USB access

How to Check If You’re Affected

Verify Your Kernel Version

Check your current kernel version:

uname -r

Compare against the patched release (next-20260710). If your version is earlier, you’re potentially affected.

For more detailed version information:

cat /proc/version

Identify Active HID Sony Driver Usage

Check if the HID Sony driver is loaded:

lsmod | grep hid_sony

If output appears, the driver is active. Verify connected devices:

lsusb | grep -i sony

Or check all HID devices:

ls -la /sys/bus/hid/devices/

Check System Logs for Indicators

Search for signs of exploitation attempts or crashes:

dmesg | grep -i "sony\|hid\|use-after-free"
journalctl -u kernel | grep -i sony

Look for:

• Kernel panics mentioning HID or Sony driver
• USB device enumeration errors
• Memory access violations

Mitigation and Remediation

Apply the Latest Kernel Patch

For Ubuntu/Debian systems:

sudo apt update
sudo apt upgrade linux-image-generic
sudo reboot

For Fedora/RHEL systems:

sudo dnf update kernel
sudo reboot

For Arch Linux:

sudo pacman -Syu
sudo reboot

Verify the patch:

uname -r
# Confirm version is next-20260710 or later

Disable the HID Sony Driver if Unnecessary

If you don’t use GHL dongles or Sony HID devices, disable the driver:

Temporary (until reboot):

sudo modprobe -r hid_sony

Permanent (add to blacklist):

echo "blacklist hid_sony" | sudo tee /etc/modprobe.d/blacklist-hid-sony.conf
sudo update-initramfs -u
sudo reboot

Temporary Workarounds

If immediate patching isn’t possible:

1. Disconnect GHL devices until patching is complete
2. Restrict USB access using physical locks or BIOS settings
3. Monitor system logs for exploitation attempts
4. Isolate affected systems from untrusted networks
5. Implement USB device policies to prevent unauthorized connections

Detection Methods

Static Code Analysis Approach

Security teams can identify the vulnerability using static analysis tools:

# Using Clang Static Analyzer
scan-build make
# Using Coverity or similar tools
cov-build --dir cov-int make
cov-analyze --dir cov-int

Look for patterns:

• Timer initialization without proper cleanup
• URB allocation/deallocation without synchronization
• Race conditions between timer callbacks and resource cleanup

Dynamic Analysis with KASAN

Enable Kernel Address Sanitizer to detect memory violations:

# Compile kernel with KASAN enabled
CONFIG_KASAN=y
CONFIG_KASAN_GENERIC=y

KASAN will report:

• Use-after-free accesses
• Double-free attempts
• Out-of-bounds memory access

Monitor kernel logs for KASAN reports:

dmesg | grep -A 10 "KASAN"

System Monitoring and Logging

Implement comprehensive logging:

# Monitor USB device connections
udevadm monitor --property
# Track driver loading/unloading
echo "module hid_sony +p" > /sys/kernel/debug/dynamic_debug/control
# Monitor system calls related to USB
auditctl -w /sys/bus/usb/ -p wa -k usb_changes

Prevention Best Practices

Kernel Update Strategy

Establish a systematic patching approach:

1. Subscribe to security advisories: Linux kernel security mailing list
2. Test patches in staging: Validate in non-production environments first
3. Schedule regular updates: Monthly or quarterly cycles
4. Maintain inventory: Track kernel versions across all systems
5. Automate where possible: Use configuration management tools

Security Monitoring Implementation

Deploy detection capabilities:

• Intrusion detection systems monitoring for exploitation patterns
• System call auditing to track suspicious driver interactions
• Memory protection using SMEP/SMAP if available
• Kernel module signing to prevent unauthorized driver loading
• SELinux/AppArmor policies restricting driver access

Hardware Inventory Management

Maintain awareness of connected devices:

• Document all HID devices in use
• Implement USB device whitelisting
• Restrict USB port access in sensitive environments
• Use USB data blockers for charging-only scenarios
• Monitor for unauthorized device connections

Frequently Asked Questions

Q: What is CVE-2026-89625 and how does it affect my system?

A: CVE-2026-89625 is a use-after-free vulnerability in the Linux kernel’s HID Sony driver. It affects systems using Guitar Hero Live dongles or other Sony HID gaming peripherals. The vulnerability can lead to kernel crashes or arbitrary code execution if exploited. If you don’t use these devices, your risk is lower but not eliminated if the driver is compiled into your kernel.

Q: How do I check if my Linux kernel version is vulnerable?

A: Run uname -r to check your kernel version. If it’s prior to the next-20260710 release, you’re potentially affected. You can also check if the HID Sony driver is loaded with lsmod | grep hid_sony. If the driver isn’t loaded and you don’t use Sony HID devices, your practical risk is minimal.

Q: Can this vulnerability be exploited without physical access to the device?

A: Exploitation typically requires the ability to connect a USB device or trigger driver unbinding, which usually requires physical access. However, in multi-user systems or systems with remote USB access, exploitation could be possible without direct physical presence. The attack complexity is high due to race condition timing requirements.

Q: What is the difference between the use-after-free condition and other memory vulnerabilities?

A: Use-after-free occurs when freed memory is accessed again. Unlike buffer overflows (writing beyond allocated memory) or null pointer dereferences, use-after-free involves legitimate memory that was properly allocated but is accessed after deallocation. This makes it particularly dangerous because the memory may be reallocated to other purposes, allowing attackers to influence what happens when it’s accessed.

Q: How long does it take to apply the patch?

A: Applying the kernel patch typically takes 15-30 minutes including download, installation, and reboot. Testing in a staging environment may add 1-2 hours. The actual patching process is straightforward; the time investment is primarily in planning and testing.

Q: If I don’t use Guitar Hero Live dongles, am I still at risk?

A: Your risk is significantly lower but not zero. If the HID Sony driver is compiled into your kernel (common in many distributions), the vulnerability exists even if no devices are connected. However, exploitation requires either connecting a malicious device or triggering driver unbinding, both of which are less likely without active device usage.

Q: What should I do if I can’t update my kernel immediately?

A: Implement temporary mitigations: disconnect any GHL dongles, blacklist the hid_sony driver module, restrict USB port access, and monitor system logs for exploitation attempts. These measures reduce your exposure while you plan for patching. Prioritize patching within 1-2 weeks.

Q: How can I monitor my system for exploitation attempts?

A: Enable kernel logging with echo "module hid_sony +p" > /sys/kernel/debug/dynamic_debug/control, monitor dmesg for crashes or KASAN reports, and use auditctl to track USB device changes. Set up alerts for kernel panics or unexpected driver behavior. Consider deploying KASAN-enabled kernels in test environments to detect exploitation.

Q: Are there any known public exploits for CVE-2026-89625?

A: As of the current advisory, no public exploits have been disclosed. However, the vulnerability is well-documented and the technical details are available, so exploit development is possible. This emphasizes the importance of patching promptly rather than relying on exploit unavailability.

Q: What is the next-20260710 release and when will it be available?

A: The next-20260710 release refers to a specific Linux kernel snapshot that includes the fix for CVE-2026-89625. This is typically a development or release candidate version. Check your distribution’s kernel repository for the corresponding stable release version that includes this fix. Most distributions will backport the fix to their supported kernel versions.

Summary and Recommendations

CVE-2026-89625 represents a significant but manageable security risk for Linux systems. The vulnerability requires specific conditions to exploit but can result in severe consequences including kernel code execution.

Immediate actions:

1. Verify your kernel version and HID driver status
2. Plan patching within your change management process
3. Implement temporary mitigations if patching is delayed
4. Monitor systems for exploitation attempts

Long-term strategy:

1. Establish regular kernel update cycles
2. Maintain hardware inventory and USB device policies
3. Deploy security monitoring for kernel-level threats
4. Subscribe to Linux security advisories

The Linux kernel community has addressed this vulnerability, and patches are available. Organizations should prioritize deployment based on their specific risk profile and operational constraints.

References

• Original Vulnerability Report: 0sec.ai Security Research
• Linux Kernel Mailing List: LKML discussions on HID Sony driver fixes
• Patch Information: Linux kernel next-20260710 release notes
• CVSS Calculator: NIST National Vulnerability Database
• Kernel Documentation: Linux kernel HID subsystem documentation
• Security Best Practices: NIST Cybersecurity Framework, CIS Controls

Article Classification: CVE Analysis | IT Security | TECH OPS
Last Updated: 2026
Review Cycle: Quarterly or upon new vulnerability information