Troubleshooting Tracee Incomplete Process Lineage Output

Jul 23, 2025 by gitftunila 57 views

Tracee's Incomplete Process Lineage Output: A Troubleshooting Guide

When using Tracee to monitor and gather information about running processes, it's essential to ensure that the tool accurately captures the process lineage. This article addresses a scenario where Tracee's lineage get command doesn't return the expected output, leading to incomplete process trees. This can be a significant issue when trying to build a versioned process tree or track process activity within a containerized environment. This comprehensive guide delves into the intricacies of diagnosing and resolving issues with Tracee's process lineage tracking, offering insights and solutions for users encountering similar challenges.

Understanding the Problem: Incomplete Process Lineage

The core issue lies in Tracee's inability to capture the complete process lineage, resulting in missing elements and unpopulated fields in the output. This problem manifests when using the proctree data source to retrieve process lineage, particularly in scenarios involving nested shells or complex process hierarchies. The user reported that the output only showed a few elements, and many fields were not populated, despite the expectation of a more comprehensive lineage.

Process lineage is the ancestry of a process, tracing back to its parent, grandparent, and so on, up to the initial process that started the chain. Accurate process lineage is crucial for security monitoring, forensic analysis, and understanding the relationships between different processes in a system. When Tracee fails to capture the complete lineage, it can lead to gaps in understanding the system's behavior and potential security risks.

Initial Observations and System Configuration

The user reported this issue on both ARM64 and AMD64 Linux systems, indicating that the problem is not architecture-specific. The following system details were provided:

Tracee Version: main-31145606f
Kernel Version: Linux mysuperhostname 6.12.0-55.14.1.el10_0.aarch64 #1 SMP PREEMPT_DYNAMIC Sat Jun 7 06:35:24 EDT 2025 aarch64 aarch64 aarch64 GNU/Linux
Tracee Command: sudo tracee --events signature_name --output json --proctree source=both

Tracee was running inside a container built using Makefile.tracee-make ubuntu-prepare, and the user accessed it via Makefile.tracee-make ubuntu-shell. The signature used was triggered by execve and designed to print the lineage, simplifying the debugging process.

Analyzing the Output

The provided output snippet reveals the following:

[
  {
    "Timestamp": "2025-07-17 09:37:03.988986784 +0000 UTC",
    "Info": {
      "EntityId": 2951109802,
      "Pid": 0,
      "NsPid": 0,
      "Ppid": 0,
      "ContainerId": "",
      "Cmd": [],
      "ExecutionBinary": {
        "Path": "",
        "Hash": "",
        "Inode": 0,
        "Device": 0,
        "Ctime": "1970-01-01 00:00:00 +0000 UTC",
        "Mode": 0
      },
      "Interpreter": {
        "Path": "",
        "Hash": "",
        "Inode": 0,
        "Device": 0,
        "Ctime": "0001-01-01 00:00:00 +0000 UTC",
        "Mode": 0
      },
      "Interp": {
        "Path": "",
        "Hash": "",
        "Inode": 0,
        "Device": 0,
        "Ctime": "0001-01-01 00:00:00 +0000 UTC",
        "Mode": 0
      },
      "StartTime": "2025-07-17 09:37:03.982908915 +0000 UTC",
      "ExecTime": "1970-01-01 00:00:00 +0000 UTC",
      "ExitTime": "1970-01-01 00:00:00 +0000 UTC",
      "ParentEntityId": 98322676,
      "ThreadsIds": {
        "85989": 2951109802
      },
      "ChildProcessesIds": {},
      "IsAlive": true
    }
  },
  {
    "Timestamp": "2025-07-17 09:37:03.982908915 +0000 UTC",
    "Info": {
      "EntityId": 98322676,
      "Pid": 69684,
      "NsPid": 69684,
      "Ppid": 0,
      "ContainerId": "",
      "Cmd": [],
      "ExecutionBinary": {
        "Path": "",
        "Hash": "",
        "Inode": 0,
        "Device": 0,
        "Ctime": "1970-01-01 00:00:00 +0000 UTC",
        "Mode": 0
      },
      "Interpreter": {
        "Path": "",
        "Hash": "",
        "Inode": 0,
        "Device": 0,
        "Ctime": "0001-01-01 00:00:00 +0000 UTC",
        "Mode": 0
      },
      "Interp": {
        "Path": "",
        "Hash": "",
        "Inode": 0,
        "Device": 0,
        "Ctime": "0001-01-01 00:00:00 +0000 UTC",
        "Mode": 0
      },
      "StartTime": "2025-07-17 09:16:48.871856178 +0000 UTC",
      "ExecTime": "1970-01-01 00:00:00 +0000 UTC",
      "ExitTime": "1970-01-01 00:00:00 +0000 UTC",
      "ParentEntityId": 0,
      "ThreadsIds": {
        "69684": 98322676
      },
      "ChildProcessesIds": {
        "85989": 2951109802
      },
      "IsAlive": true
    }
  }
]

The output shows two processes, but key fields like Cmd, ExecutionBinary, Interpreter, and Interp are empty. This suggests that Tracee is not correctly capturing the process information, leading to an incomplete lineage.

Potential Causes and Troubleshooting Steps

To effectively troubleshoot this issue, consider the following potential causes and corresponding steps:

1. Insufficient Permissions

Problem: Tracee requires sufficient permissions to access process information. If Tracee doesn't have the necessary privileges, it may fail to collect complete data.
Solution: Ensure Tracee is running with sudo or as a user with the required capabilities. Check the Tracee documentation for specific permission requirements.

2. Containerization Issues

Problem: Running Tracee inside a container can introduce complexities, especially with namespace isolation. If Tracee isn't configured correctly, it may not be able to access processes outside its container.
Solution: Verify that Tracee is running with the necessary flags to access the host's process namespace. The --proctree source=both flag suggests an attempt to capture processes from both the container and the host, but further configuration might be needed. Ensure that the container has the necessary capabilities, such as SYS_PTRACE and SYS_ADMIN.

3. Event Filtering and Signatures

Problem: The signature being used might not be capturing the relevant events or might be filtering out crucial information.
Solution: Review the signature to ensure it's correctly triggered by execve events and that it's not inadvertently filtering out necessary process data. Simplify the signature further to rule out any complex logic issues.

4. Tracee Configuration

Problem: Incorrect Tracee configuration can lead to incomplete data collection. For example, specific command-line options or configuration files might be misconfigured.
Solution: Double-check the Tracee command-line options, especially those related to output and data sources. Ensure that the proctree data source is correctly configured and that no other settings are interfering with its operation. The use of --output json is correct for structured output, but other options might need adjustment.

5. Kernel Compatibility

Problem: Tracee relies on kernel features to collect process information. Incompatibilities between Tracee and the kernel version can cause issues.
Solution: Verify that the Tracee version is compatible with the kernel version. Check the Tracee documentation or release notes for any known compatibility issues. The kernel version 6.12.0-55.14.1.el10_0.aarch64 is relatively recent, so compatibility is less likely to be the primary issue, but it's still worth considering.

6. Resource Constraints

Problem: Insufficient resources (CPU, memory) can prevent Tracee from capturing all process information, especially in high-load environments.
Solution: Monitor the resource usage of the Tracee container. Ensure that the container has enough resources to operate efficiently. If resource constraints are identified, allocate more resources to the container.

7. Bugs in Tracee

Problem: There might be undiscovered bugs in Tracee that cause incomplete lineage data.
Solution: Check the Tracee issue tracker on GitHub for similar reports. If a bug is suspected, consider filing a new issue with detailed information about the problem, including the Tracee version, kernel version, command-line options, and any relevant logs.

Detailed Troubleshooting Steps

To systematically address the issue, follow these steps:

1. Verify Permissions

Ensure Tracee is running with sudo or as a user with the necessary capabilities. Check the Tracee documentation for specific permission requirements.

sudo tracee --events signature_name --output json --proctree source=both

2. Check Container Configuration

Verify that the Tracee container has the necessary capabilities and is configured to access the host's process namespace. This might involve adjusting the container's security context or using host networking.

3. Simplify the Signature

Create a minimal signature that only captures the execve event and prints the process lineage. This helps isolate the issue and rule out any problems with the signature logic.

// Minimal signature to capture execve events and print lineage
package main

import (
	"fmt"

	"github.com/aquasecurity/tracee/pkg/events"
	"github.com/aquasecurity/tracee/types/detect"
)

var Signature = detect.Signature{
	Metadata: detect.Metadata{
		Name:        "execve_lineage",
		Description: "Captures execve events and prints lineage",
		Version:     "0.1.0",
		Author:      "Your Name",
	},
	GetSelectedEvents: func() []detect.SignatureEvent {
		return []detect.SignatureEvent{{
			Event: events.Execve,
			Arguments: nil,
		}}
	},

	OnEvent: func(event detect.Event, ctx detect.Context) error {
		lineage, err := ctx.GetProcessLineage(event.ProcessContext.ProcessID)
		if err != nil {
			return fmt.Errorf("error getting lineage: %v", err)
		}
		fmt.Printf("Lineage for PID %d: %+v\n", event.ProcessContext.ProcessID, lineage)
		return nil
	},
}

4. Review Tracee Command-Line Options

Double-check the command-line options, especially those related to output and data sources. Ensure that the proctree data source is correctly configured.

sudo tracee --events ./minimal_signature.rego --output json --proctree source=both

5. Check Kernel Compatibility

Verify that the Tracee version is compatible with the kernel version. Check the Tracee documentation or release notes for any known compatibility issues.

6. Monitor Resource Usage

Monitor the resource usage of the Tracee container to ensure it has enough resources to operate efficiently.

docker stats <container_id>

7. Examine Tracee Logs

Check Tracee logs for any error messages or warnings that might indicate the cause of the problem. Tracee logs can provide valuable insights into its operation and any issues it encounters.

8. Test Outside the Container

Run Tracee directly on the host system (outside the container) to see if the issue persists. This can help determine if the problem is related to the container environment.

Advanced Troubleshooting Techniques

If the basic troubleshooting steps don't resolve the issue, consider these advanced techniques:

1. Debugging with `strace`

Use strace to trace the system calls made by Tracee. This can help identify if Tracee is encountering any errors when trying to access process information.

sudo strace -f -p <tracee_pid> -o tracee.log

2. Using `perf` to Profile Tracee

Use perf to profile Tracee's performance. This can help identify any performance bottlenecks that might be preventing Tracee from capturing all process information.

sudo perf record -g -p <tracee_pid> -- sleep 30
sudo perf report

3. Examining eBPF Programs

Tracee uses eBPF programs to collect data. Examining these programs can provide insights into how Tracee is collecting process information and whether there are any issues with the programs themselves. This requires a deep understanding of eBPF and Tracee's internal architecture.

Conclusion

Troubleshooting incomplete process lineage output in Tracee requires a systematic approach. By following the steps outlined in this guide, you can identify the root cause of the issue and implement the appropriate solution. Remember to verify permissions, check container configurations, simplify signatures, and monitor resource usage. If the problem persists, consider advanced debugging techniques and consult the Tracee documentation or community for further assistance. Accurately capturing process lineage is crucial for effective security monitoring and incident response, so resolving this issue is paramount for leveraging Tracee's full potential.

By addressing these potential issues and systematically troubleshooting, you can ensure that Tracee accurately captures process lineage, providing a comprehensive view of system activity and enhancing your security posture.

Tracee, process lineage, troubleshooting, container security, eBPF, system monitoring, debugging, security analysis, incident response, kernel compatibility, permissions, signatures, resource usage, strace, perf, process information, event filtering, containerization issues

What is process lineage and why is it important?

Process lineage refers to the chain of parent-child relationships between processes in a system. It's crucial for security monitoring, as it helps trace the origin of processes and identify potentially malicious activities. By understanding the lineage, you can track how a process was spawned and what other processes it interacted with, providing valuable context for security investigations.

Why is Tracee not capturing the complete process lineage?

Several factors can cause Tracee to capture incomplete process lineage, including insufficient permissions, containerization issues, incorrect event filtering, kernel incompatibilities, and resource constraints. Each of these potential causes requires specific troubleshooting steps to identify and resolve the problem.

How can I verify if Tracee has sufficient permissions?

Ensure that Tracee is running with sudo or as a user with the necessary capabilities, such as SYS_PTRACE and SYS_ADMIN. These capabilities allow Tracee to access process information across the system. Check the Tracee documentation for the specific permissions required.

What container configuration issues can affect Tracee's process lineage capture?

When running Tracee inside a container, namespace isolation can prevent it from accessing processes outside the container. Ensure that Tracee is configured to access the host's process namespace, potentially by adjusting the container's security context or using host networking.

How can I simplify the Tracee signature to troubleshoot lineage capture issues?

Create a minimal signature that only captures the execve event and prints the process lineage. This helps isolate the issue and rule out any problems with the signature logic. By focusing on the essential event and data, you can simplify the debugging process.

What should I check if I suspect kernel incompatibility?

Verify that the Tracee version is compatible with the kernel version. Check the Tracee documentation or release notes for any known compatibility issues. Kernel incompatibilities can prevent Tracee from correctly accessing kernel data structures and events.

How do resource constraints impact Tracee's ability to capture process lineage?

Insufficient resources (CPU, memory) can prevent Tracee from capturing all process information, especially in high-load environments. Monitor the resource usage of the Tracee container or host system to ensure it has enough resources to operate efficiently.

What are advanced troubleshooting techniques for Tracee's process lineage issues?

Advanced techniques include using strace to trace system calls, perf to profile Tracee's performance, and examining eBPF programs. These methods provide deeper insights into Tracee's operation and can help identify complex issues.

Where can I find Tracee logs and how can they help with troubleshooting?

Tracee logs can provide valuable insights into its operation and any issues it encounters. Check the default log location or any custom log path configured for Tracee. Log messages may contain error messages, warnings, or other information that can help diagnose the problem.

Should I test Tracee outside the container to troubleshoot lineage issues?

Yes, running Tracee directly on the host system (outside the container) can help determine if the problem is related to the container environment. If the issue persists outside the container, it indicates a problem with Tracee's configuration or the host system.

What is the significance of the `--proctree source=both` flag in the Tracee command?

The --proctree source=both flag instructs Tracee to capture process information from both the container and the host. This is particularly useful in containerized environments where processes may span across container boundaries. However, additional configuration might be needed to ensure proper access to the host's process namespace.