CVE-2022-49801
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's tracing subsystem, specifically in the tracing_read_pipe() function. The vulnerability allows unprivileged local users to cause a kernel memory leak by reading from trace pipes, potentially leading to denial of service through resource exhaustion. All Linux systems with the affected kernel versions 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 →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 attacker could repeatedly trigger the memory leak to exhaust kernel memory, causing system instability, crashes, or denial of service affecting all users and services on the system.
Likely Case
Local users could cause gradual memory consumption leading to performance degradation or system instability over time, particularly on systems with frequent tracing operations.
If Mitigated
With proper access controls limiting trace pipe access to privileged users only, the impact is minimal as only authorized users could trigger the vulnerability.
🎯 Exploit Status
Exploitation requires local access to the system; the vulnerability is in a core kernel component but has limited impact scope (memory leak rather than code execution).
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 2c21ee020ce43d744ecd7f3e9bddfcaafef270ce, 649e72070cbbb8600eb823833e4748f5a0815116, a7d3f8f33c113478737bc61bb32ec5f9a987da7d
Vendor Advisory: https://git.kernel.org/stable/c/2c21ee020ce43d744ecd7f3e9bddfcaafef270ce
Restart Required: Yes
Instructions:
1. Update to a patched kernel version from your Linux distribution vendor. 2. Reboot the system to load the new kernel. 3. Verify the fix is applied by checking kernel version or testing the vulnerability.
🔧 Temporary Workarounds
Restrict trace pipe access
linuxLimit access to trace pipes to privileged users only to prevent unprivileged exploitation
chmod 600 /sys/kernel/debug/tracing/trace_pipe
echo 1 > /proc/sys/kernel/perf_event_paranoid
Disable tracing subsystem
linuxCompletely disable kernel tracing if not required
echo 0 > /sys/kernel/debug/tracing/tracing_on
echo nop > /sys/kernel/debug/tracing/current_tracer
🧯 If You Can't Patch
- Implement strict access controls on /sys/kernel/debug/tracing to limit access to trusted administrators only
- Monitor system memory usage and kernel logs for signs of memory exhaustion or repeated trace pipe access attempts
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from your distribution; test by reading from trace pipes while monitoring memory usageCheck Version:
uname -rVerify Fix Applied:
After patching, verify the kernel version includes the fix commits; test that reading from trace pipes no longer causes memory leaks📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- High memory usage in kernel space
- Frequent access to trace pipes in audit logs
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Process monitoring for repeated reads from /sys/kernel/debug/tracing/trace_pipe combined with memory consumption alerts