Linux security modules: general security support for the linux kernel

Abstract

The access control mechanisms of existing mainstream operating systems are inadequate to provide strong system security. Enhanced access control mechanisms have failed to win acceptance into mainstream operating systems due in part to a lack of consensus within the security community on the right solution. Since generalpurpose operating systems must satisfy a wide range of user requirements, any access control mechanism integrated into such a system must be capable of supporting many different access control models. The Linux Security Modules (LSM) project has developed a lightweight, general purpose, access control framework for the mainstream Linux kernel that enables many different access control models to be implemented as loadable kernel modules. A number of existing enhanced access control implementations, including Linux capabilities, SecurityEnhanced Linux (SELinux), and Domain and Type Enforcement (DTE), have already been adapted to use the LSM framework. This paper presents the design and implementation of LSM and discusses the challenges in providing a truly general solution that minimally impacts the Linux kernel.

SoK: Introspections on Trust and the Semantic Gap

“…An attacker overwrites a function pointer with the address of a function provided by the attacker, which will then allow the attacker to interpose on a desired set of kernel operations. In some sense, Linux Security Modules provide similar hooks for security enhancements [91]; the primary difference is that KOH repurposes other hooks used for purposes such as implementing an extensible virtual file system (VFS) model. The defenses against KOH attacks generally depend on whether the hook is located in the text or data segment.…”

“…A legacy OS, such as Linux, executes all security modules in the same address space and with the same privilege level as the rest of the kernel [91]. When this is coupled with a porous attack surface, malicious software can often load code into the OS kernel which disables security measures, such as virus scanners and intrusion detection.…”

Pastures: Towards Usable Security Policy Engineering

“…Privileges are managed at much higher levels of granularity and security labels are applied on zone level rather than on individual resource level as in SELinux, with no concept of label transitions within a zone. The designers apparently eschewed the flexibility of the LSM/SELinux approach [14,3] in favor of a simpler conceptual model that is easier to use.…”

Task‐Oriented Multilevel Cooperative Access Control Scheme for Environment with Virtualization and IoT

“…Therefore, a system which has implemented the BLP model is secure and could protect the privacy between information sharing. [21] is a framework in the Linux kernel that supports various computer security models and LSM has nothing to do with any separate security implementation. This framework is licensed under the GNU General Public License and it has been a part of the official Linux kernel since Linux 2.6.…”