CVE-2022-50231
📋 TL;DR
This is a read out-of-bounds vulnerability in the ARM64 Poly1305 cryptographic implementation in the Linux kernel. It allows attackers to read kernel memory beyond allocated boundaries, potentially leaking sensitive information. Systems running affected Linux kernel versions with ARM64 architecture and Poly1305 crypto usage are vulnerable.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory disclosure leading to privilege escalation, sensitive data exposure, or system crash/DoS.
Likely Case
Information disclosure of kernel memory contents, potentially including cryptographic keys or other sensitive data.
If Mitigated
Limited impact due to KASAN detection or system crash without data compromise.
🎯 Exploit Status
Proof-of-concept code provided in CVE description. Exploitation requires ability to trigger Poly1305 operations with specific malformed input.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commit 3c77292d52b341831cb09c24ca4112a1e4f9e91f and backported to stable branches
Vendor Advisory: https://git.kernel.org/stable/c/3c77292d52b341831cb09c24ca4112a1e4f9e91f
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable Poly1305 module
linuxPrevent loading of vulnerable Poly1305 ARM64 module
echo 'blacklist poly1305_neon' > /etc/modprobe.d/disable-poly1305.conf
rmmod poly1305_neon
🧯 If You Can't Patch
- Implement strict access controls to limit who can perform cryptographic operations
- Monitor for kernel crashes or KASAN reports indicating exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if system is ARM64 and Poly1305 module is loaded: 'uname -m' should show aarch64 and 'lsmod | grep poly1305' shows module loadedCheck Version:
uname -rVerify Fix Applied:
Check kernel version against patched versions from your distribution vendor📡 Detection & Monitoring
Log Indicators:
- KASAN reports of slab-out-of-bounds reads in poly1305_neon
- Kernel panic/crash logs during crypto operations
Network Indicators:
- Unusual cryptographic operation patterns
SIEM Query:
kernel: *KASAN* AND *poly1305* AND *slab-out-of-bounds*🔗 References
- https://git.kernel.org/stable/c/3c77292d52b341831cb09c24ca4112a1e4f9e91f
- https://git.kernel.org/stable/c/3d4c28475ee352c440b83484b72b1320ff76364a
- https://git.kernel.org/stable/c/7ae19d422c7da84b5f13bc08b98bd737a08d3a53
- https://git.kernel.org/stable/c/8d25a08599df7ca3093eb7ca731c7cd41cbfbb51
- https://git.kernel.org/stable/c/d069dcffef849b8fd10030fd73007a79612803e6
