CVE-2023-52649
📋 TL;DR
This CVE describes an out-of-bounds read vulnerability in the Linux kernel's VKMS (Virtual Kernel Mode Setting) driver. When processing LUT (Look-Up Table) arrays, the driver could read beyond the allocated memory boundary, potentially exposing kernel memory contents. This affects systems using the VKMS driver, typically in virtualized or testing environments.
💻 Affected Systems
- Linux kernel with VKMS driver enabled
📦 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
Kernel memory disclosure leading to information leakage, which could be combined with other vulnerabilities to achieve privilege escalation or system compromise.
Likely Case
Information disclosure of kernel memory contents, potentially exposing sensitive data or memory layout information to attackers.
If Mitigated
Minimal impact if VKMS driver is not in use or if proper kernel hardening measures are implemented.
🎯 Exploit Status
Exploitation requires local access and ability to trigger VKMS LUT operations. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 046c1184ce60b0a37d48134f17ddbc1f32ce02bd and related commits
Vendor Advisory: https://git.kernel.org/stable/c/046c1184ce60b0a37d48134f17ddbc1f32ce02bd
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Check if VKMS module is loaded. 3. Reboot system to load patched kernel.
🔧 Temporary Workarounds
Disable VKMS module
linuxPrevent loading of the vulnerable VKMS driver
echo 'blacklist vkms' >> /etc/modprobe.d/blacklist-vkms.conf
rmmod vkms
🧯 If You Can't Patch
- Ensure VKMS driver is not loaded (check with 'lsmod | grep vkms')
- Implement strict access controls to prevent unauthorized local users from accessing graphics subsystems
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if VKMS module is loaded: 'uname -r' and 'lsmod | grep vkms'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is patched and VKMS module version matches fixed commits📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages related to VKMS or memory access violations
- System logs showing VKMS module loading
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("vkms" OR "out of bounds" OR "general protection fault")🔗 References
- https://git.kernel.org/stable/c/046c1184ce60b0a37d48134f17ddbc1f32ce02bd
- https://git.kernel.org/stable/c/2fee84030d12d9fddfa874e4562d71761a129277
- https://git.kernel.org/stable/c/92800aaeff51b8358d1e0a7eb74daf8aa2d7ce9d
- https://git.kernel.org/stable/c/9556c167673057d48ce4a0da675026fe046654c1
- https://git.kernel.org/stable/c/046c1184ce60b0a37d48134f17ddbc1f32ce02bd
- https://git.kernel.org/stable/c/2fee84030d12d9fddfa874e4562d71761a129277
- https://git.kernel.org/stable/c/92800aaeff51b8358d1e0a7eb74daf8aa2d7ce9d
- https://git.kernel.org/stable/c/9556c167673057d48ce4a0da675026fe046654c1
