Embedded Linux Kernel Security via Capability Segmentation
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Solution Overview
Problem
Conventional security methods for embedded Linux systems, which operate in a single-user environment, are inefficient and insecure as they grant all privileges to application program processors, leading to unnecessary access and potential threats.
Innovation Solution
An application program launching method that assigns a unique user identification and capability to each application program processor, configuring a basic directory and storing security settings in a registry to restrict privileges and isolate file access, mimicking a multi-user environment without modifying existing security methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If application program processors are executed with the root account having all superuser privileges, then the application programs can access the Linux kernel without limitation and execute all operations, but the security of the embedded system deteriorates because unnecessary access and potential threats increase
Solution Approach 1:
The patent segments superuser privileges into distinct capability sets. Instead of granting all privileges to all application processors, the system divides privileges into different capability levels (e.g., CAP_NET_ADMIN, CAP_SYS_ADMIN) that can be selectively assigned to different application processors based on their specific needs, thereby reducing unnecessary access while maintaining operational functionality.
Solution Approach 2:
The patent applies local quality by assigning different capability sets to different application processors based on their specific operational requirements. Each application processor receives only the minimal necessary privileges needed for its function, rather than uniformly granting all superuser privileges to all processors, thus improving security without compromising local operational needs.
2Reliability
If conventional multi-user security methods are applied to single-user embedded systems, then user account separation is implemented, but the system complexity increases and usability deteriorates because user accounts are not needed in single-user environment
Solution Approach 1:
The patent extracts the essential security function from the complex multi-user account management system. Instead of implementing full user account separation with login, authentication, and permission management, the system extracts only the core capability-based access control mechanism, applying it to single-user embedded systems to maintain security without the complexity of traditional multi-user account management.
Solution Approach 2:
The patent applies partial action by implementing capability-based access control without the full suite of multi-user security features. The system provides sufficient security through capability sets and access control lists while omitting unnecessary components like user login systems, authentication mechanisms, and detailed permission hierarchies, thus reducing complexity while maintaining essential security functions.
3Adaptability or versatility
If application programs are executed with root account privileges, then all operations can be performed without restriction, but the loss of information increases because file access is not isolated and unnecessary system access occurs
Solution Approach 1:
The patent segments file access rights through capability sets and access control lists. Instead of allowing unrestricted file access with root privileges, the system divides file access into specific capabilities (e.g., read, write, execute) that can be selectively granted to different application processors based on their operational needs, thereby preventing unnecessary information access while maintaining necessary operational versatility.
Data Source
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AI summary
Provided is an application program launching method and system for improving security of an embedded Linux kernel by distributing superuser privileges. The method includes: searching security set information on an application program selected by a user; changing a user account for a processor of the application program to a user ID associated with the application program in the security set information; setting a capability for the processor according to setting information for the capability in the security set information; changing a basic directory for the processor according to a basic directory in the security set information; and launching the application program.