CVE-2024-36910
📋 TL;DR
This vulnerability in the Linux kernel's uio_hv_generic driver could allow an untrusted hypervisor in Confidential Computing (CoCo) virtual machines to cause memory decryption failures, potentially exposing sensitive memory contents. It affects Linux systems using Hyper-V VMBus device UIO drivers in CoCo VM environments. The issue could lead to information disclosure of kernel memory.
💻 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 →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
An untrusted hypervisor could exploit this to read sensitive kernel memory contents, potentially exposing encryption keys, credentials, or other protected data from the guest VM.
Likely Case
Information disclosure of kernel memory to the hypervisor, potentially revealing system state or sensitive data but not direct code execution.
If Mitigated
With proper CoCo VM isolation and hypervisor controls, the risk is limited to information disclosure within the affected VM.
🎯 Exploit Status
Exploitation requires hypervisor-level access and ability to trigger set_memory_decrypted() failures in CoCo VM environments.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check kernel versions containing commits: 3d788b2fbe6a1a1a9e3db09742b90809d51638b7, 6466a0f6d235c8a18c602cb587160d7e49876db9, dabf12bf994318d939f70d47cfda30e47abb2c54, fe2c58602354fbd60680dc42ac3a0b772cda7d23
Vendor Advisory: https://git.kernel.org/stable/c/3d788b2fbe6a1a1a9e3db09742b90809d51638b7
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check with your distribution for specific kernel package updates. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable uio_hv_generic driver
linuxRemove or blacklist the vulnerable driver if not required
echo 'blacklist uio_hv_generic' >> /etc/modprobe.d/blacklist.conf
rmmod uio_hv_generic
Avoid CoCo VM deployment
allDo not use Confidential Computing VM environments until patched
🧯 If You Can't Patch
- Isolate CoCo VMs from untrusted hypervisors
- Monitor for unusual hypervisor behavior or memory access patterns
🔍 How to Verify
Check if Vulnerable:
Check if uio_hv_generic module is loaded: lsmod | grep uio_hv_generic. Check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits. Check that uio_hv_generic driver functions correctly in CoCo VM environment.📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing uio_hv_generic errors
- Hypervisor logs showing unusual memory operations
Network Indicators:
- Unusual VMBus traffic patterns
SIEM Query:
Search for kernel module load/unload events related to uio_hv_generic or memory decryption failures🔗 References
- https://git.kernel.org/stable/c/3d788b2fbe6a1a1a9e3db09742b90809d51638b7
- https://git.kernel.org/stable/c/6466a0f6d235c8a18c602cb587160d7e49876db9
- https://git.kernel.org/stable/c/dabf12bf994318d939f70d47cfda30e47abb2c54
- https://git.kernel.org/stable/c/fe2c58602354fbd60680dc42ac3a0b772cda7d23
- https://git.kernel.org/stable/c/3d788b2fbe6a1a1a9e3db09742b90809d51638b7
- https://git.kernel.org/stable/c/6466a0f6d235c8a18c602cb587160d7e49876db9
- https://git.kernel.org/stable/c/dabf12bf994318d939f70d47cfda30e47abb2c54
- https://git.kernel.org/stable/c/fe2c58602354fbd60680dc42ac3a0b772cda7d23
