CVE-2022-49994
📋 TL;DR
This CVE describes a memory leak detection issue in the Linux kernel's bootmem subsystem. When freeing vmemmap pages, kmemleak (kernel memory leak detector) fails to properly remove tracking, causing false positive memory leak reports that can disable kmemleak functionality. This affects Linux systems with kmemleak enabled.
💻 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
kmemleak becomes disabled, preventing detection of actual memory leaks which could mask more serious vulnerabilities or system instability.
Likely Case
kmemleak generates false positive reports and may stop working, reducing debugging capability but not directly compromising system security.
If Mitigated
With kmemleak disabled or not in use, no operational impact occurs.
🎯 Exploit Status
This is not an exploitable vulnerability in the traditional sense - it's a bug in a debugging tool that causes false positives and tool disablement.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 16a12ee619e39e8112f61b603255c16b73b6264b, 9ae15c4ba2be1e5a62503b6d873e84beb5fcbb5a, or dd0ff4d12dd284c334f7e9b07f8f335af856ac78
Vendor Advisory: https://git.kernel.org/stable/c/16a12ee619e39e8112f61b603255c16b73b6264b
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable kmemleak
linuxTurn off kmemleak memory leak detection to avoid the issue
echo 0 > /sys/kernel/debug/kmemleak
🧯 If You Can't Patch
- Disable kmemleak via kernel command line or sysfs interface
- Use production kernel configurations that don't enable kmemleak
🔍 How to Verify
Check if Vulnerable:
Check if kmemleak is enabled: cat /sys/kernel/debug/kmemleak 2>/dev/null || echo 'kmemleak not enabled'Check Version:
uname -rVerify Fix Applied:
Check kernel version includes fix commits: uname -r and verify with distribution patch notes📡 Detection & Monitoring
Log Indicators:
- kmemleak: Cannot insert ... into the object search tree
- kmemleak: Kernel memory leak detector disabled
Network Indicators:
- None - this is a local kernel issue
SIEM Query:
Search for 'kmemleak' and 'disabled' in kernel logs