CVE-2023-53625
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's Intel GVT (Graphics Virtualization Technology) driver. When removing a virtual GPU (vGPU) via debugfs during driver unload, the system attempts to access debugfs root after it has already been destroyed, causing a kernel oops and potential system crash. This affects systems using Intel GVT-g for GPU virtualization with specific Intel integrated graphics.
💻 Affected Systems
- Linux kernel with Intel GVT-g support
⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially requiring physical reboot.
Likely Case
System instability or crash when removing vGPU devices or unloading the i915 driver, causing service disruption.
If Mitigated
Minor service interruption during driver maintenance operations.
🎯 Exploit Status
Requires local access and ability to trigger vGPU removal operations. Not easily weaponized for privilege escalation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 44c0e07e3972e3f2609d69ad873d4f342f8a68ec and others listed in references
Vendor Advisory: https://git.kernel.org/stable/c/44c0e07e3972e3f2609d69ad873d4f342f8a68ec
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable Intel GVT-g
linuxDisable GPU virtualization feature if not required
echo 'blacklist kvmgt' > /etc/modprobe.d/disable-kvmgt.conf
rmmod kvmgt
update-initramfs -u
Avoid vGPU removal operations
linuxPrevent triggering the vulnerable code path by avoiding vGPU removal
🧯 If You Can't Patch
- Restrict local access to prevent malicious users from triggering the vulnerability
- Avoid removing vGPU devices or unloading i915 driver while system is in production use
🔍 How to Verify
Check if Vulnerable:
Check if system has Intel GVT-g enabled: lsmod | grep kvmgt && dmesg | grep -i gvtCheck Version:
uname -rVerify Fix Applied:
Check kernel version against patched versions from kernel git commits📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages in dmesg/system logs
- NULL pointer dereference at address 0000000000000150
- Call trace showing intel_gvt_debugfs_remove_vgpu
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "Oops" OR "intel_gvt")🔗 References
- https://git.kernel.org/stable/c/44c0e07e3972e3f2609d69ad873d4f342f8a68ec
- https://git.kernel.org/stable/c/704f3384f322b40ba24d958473edfb1c9750c8fd
- https://git.kernel.org/stable/c/af90f8b36d78544433a48a3eda6a5faeafacd0a1
- https://git.kernel.org/stable/c/f5a9bbf962e2c4b1d9addbfaf16d7ffcc2f63bde
- https://git.kernel.org/stable/c/ffa83fba2a2ce8010eb106c779378cb3013362c7
