CVE-2023-52801
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's IOMMUFD subsystem allows attackers to corrupt memory when splitting I/O page table areas. This affects Linux systems with IOMMUFD enabled, potentially leading to kernel crashes or privilege escalation. The vulnerability requires local access to exploit.
💻 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 →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 panic leading to system crash or local privilege escalation to root, potentially allowing full system compromise.
Likely Case
Kernel crash causing system instability or denial of service, requiring reboot to restore functionality.
If Mitigated
Minimal impact if IOMMUFD is disabled or systems are properly patched with kernel updates.
🎯 Exploit Status
Requires local access and knowledge of IOMMUFD subsystem. Exploitation likely requires specific conditions to trigger the use-after-free.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 836db2e7e4565d8218923b3552304a1637e2f28d and e7250ab7ca4998fe026f2149805b03e09dc32498
Vendor Advisory: https://git.kernel.org/stable/c/836db2e7e4565d8218923b3552304a1637e2f28d
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable IOMMUFD
linuxDisable the IOMMUFD subsystem if not required for system functionality
Add 'iommu=off' or 'iommu.passthrough=1' to kernel boot parameters
🧯 If You Can't Patch
- Disable IOMMUFD subsystem via kernel boot parameters
- Restrict local user access and implement strict privilege separation
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if IOMMUFD is enabled: 'uname -r' and check kernel config for CONFIG_IOMMUFDCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to include the fix commits, then test IOMMUFD functionality📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Use-after-free error messages in kernel logs
- System crash/reboot events
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("panic" OR "use-after-free" OR "UAF") AND "iommufd"🔗 References
- https://git.kernel.org/stable/c/836db2e7e4565d8218923b3552304a1637e2f28d
- https://git.kernel.org/stable/c/e7250ab7ca4998fe026f2149805b03e09dc32498
- https://git.kernel.org/stable/c/fcb32111f01ddf3cbd04644cde1773428e31de6a
- https://git.kernel.org/stable/c/836db2e7e4565d8218923b3552304a1637e2f28d
- https://git.kernel.org/stable/c/e7250ab7ca4998fe026f2149805b03e09dc32498
- https://git.kernel.org/stable/c/fcb32111f01ddf3cbd04644cde1773428e31de6a
