CVE-2022-50434
📋 TL;DR
This is a memory leak vulnerability in the Linux kernel's block multi-queue (blk-mq) subsystem that occurs when hardware context registration fails during device initialization. It affects Linux systems using block storage devices, potentially leading to kernel memory exhaustion over time. The vulnerability requires local access to trigger.
💻 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 →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
Sustained exploitation could lead to kernel memory exhaustion, causing system instability, crashes, or denial of service through resource depletion.
Likely Case
Local users could trigger the memory leak through fault injection or specific device operations, gradually consuming kernel memory and potentially degrading system performance.
If Mitigated
With proper access controls and monitoring, impact is limited to local denial of service rather than privilege escalation or remote compromise.
🎯 Exploit Status
Exploitation requires local access and specific fault injection conditions during device initialization
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with fixes available (see references)
Vendor Advisory: https://git.kernel.org/stable/c/02bc8bc6eab03c84373281b85cb6e98747172ff7
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 matches patched release.
🔧 Temporary Workarounds
Restrict local access
linuxLimit local user access to systems to reduce attack surface
Monitor kernel memory usage
linuxImplement monitoring for unusual kernel memory consumption patterns
cat /proc/meminfo | grep Slab
slabtop
vmstat -s
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges
- Monitor system logs for repeated device initialization failures and kernel memory exhaustion warnings
🔍 How to Verify
Check if Vulnerable:
Check kernel version against patched releases from your distribution. Vulnerable if using unpatched kernel with blk-mq support.Check Version:
uname -rVerify Fix Applied:
Verify kernel version matches patched release from your distribution's security updates.📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages related to blk_mq_register_hctx
- Memory allocation failures in kernel logs
- Repeated device initialization failures
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("blk_mq_register_hctx" OR "kmalloc_node_trace" OR "memory allocation failure")🔗 References
- https://git.kernel.org/stable/c/02bc8bc6eab03c84373281b85cb6e98747172ff7
- https://git.kernel.org/stable/c/33e8a3f61814ea30615d0fafaf50477975d6c1ca
- https://git.kernel.org/stable/c/4b7a21c57b14fbcd0e1729150189e5933f5088e9
- https://git.kernel.org/stable/c/4b7fafa5f39b15c3a6ca3b95e534d05d6904cc95
- https://git.kernel.org/stable/c/654870789c3c1b9763316ef1c71d7a449127b175
- https://git.kernel.org/stable/c/87fd18016a47ea8ae12641377a390172c4aa97a7
- https://git.kernel.org/stable/c/cb186eb47fb9dd327bdefa15f0c5fc55c53a40dd
- https://git.kernel.org/stable/c/e8022da1fa2fdf2fa204b445dd3354e7a66d085a
- https://git.kernel.org/stable/c/eff45bfbc25a2509a6362dea6e699e14083c693c
