Library OSes are a promising approach for applications to efficiently obtain the benefits of virtual machines, including security isolation, host platform compatibility, and migration. Library OSes refactor a traditional OS kernel into an application library, avoiding overheads incurred by duplicate functionality. When compared to running a single application on an OS kernel in a VM, recent library OSes reduce the memory footprint by an order-of-magnitude.Previous library OS (libOS) research has focused on single-process applications, yet many Unix applications, such as network servers and shell scripts, span multiple processes. Key design challenges for a multi-process libOS include management of shared state and minimal expansion of the security isolation boundary. This paper presents Graphene, a library OS that seamlessly and efficiently executes both single and multi-process applications, generally with low memory and performance overheads. Graphene broadens the libOS paradigm to support secure, multi-process APIs, such as copy-on-write fork, signals, and System V IPC. Multiple libOS instances coordinate over pipe-like byte streams to implement a consistent, distributed POSIX abstraction. These coordination streams provide a simple vantage point to enforce security isolation.

Abstract-An essential goal of Virtual Machine Introspection (VMI) is assuring security policy enforcement and overall functionality in the presence of an untrustworthy OS. A fundamental obstacle to this goal is the difficulty in accurately extracting semantic meaning from the hypervisor's hardwarelevel view of a guest OS, called the semantic gap. Over the twelve years since the semantic gap was identified, immense progress has been made in developing powerful VMI tools.Unfortunately, much of this progress has been made at the cost of reintroducing trust into the guest OS, often in direct contradiction to the underlying threat model motivating the introspection. Although this choice is reasonable in some contexts and has facilitated progress, the ultimate goal of reducing the trusted computing base of software systems is best served by a fresh look at the VMI design space.This paper organizes previous work based on the essential design considerations when building a VMI system, and then explains how these design choices dictate the trust model and security properties of the overall system. The paper then observes portions of the VMI design space which have been under-explored, as well as potential adaptations of existing techniques to bridge the semantic gap without trusting the guest OS.Overall, this paper aims to create an essential checkpoint in the broader quest for meaningful trust in virtualized environments through VM introspection.

This paper presents a study of Linux API usage across all applications and libraries in the Ubuntu Linux 15.04 distribution. We propose metrics for reasoning about the importance of various system APIs, including system calls, pseudo-files, and libc functions. Our metrics are designed for evaluating the relative maturity of a prototype system or compatibility layer, and this paper focuses on compatibility with Linux applications. This study uses a combination of static analysis to understand API usage and survey data to weight the relative importance of applications to end users. This paper yields several insights for developers and researchers, which are useful for assessing the complexity and security of Linux APIs. For example, every Ubuntu installation requires 224 system calls, 208 ioctl, fcntl, and prctl codes and hundreds of pseudo files. For each API type, a significant number of APIs are rarely used, if ever. Moreover, several security-relevant API changes, such as replacing access with faccessat, have met with slow adoption. Finally, hundreds of libc interfaces are effectively unused, yielding opportunities to improve security and efficiency by restructuring libc.

Screening and identifying a disease-specific novel drug target is the first step towards a rational drug designing approach. Due to the advent of high throughput data generation techniques, the protein search space has now exceeded 24,500 human protein coding genes, which encodes approximately 1804proteins. This work aims at mining out the relationship between target proteins, drugs, and diseases genes through a network-based systems biology approach. A network of all FDA approved drugs, along with their targets were utilized to construct the proposed Drug Target (DT) network. Further, the experimental drugs were mapped into the DT network to infer the functional relationship by utilizing the respective network attributes. Similar to the DT network, a network of disease genes was created through OMIM Gene Map and Morbid Map, to link the binary associations of disorder-disease genes. In the proposed model of Human Interactome Network, shortest path length between the target protein and disease gene was used to infer the correlation between 'Drug Targets' and 'Disease-Gene'. This network-based study will help researchers to analyze, infer and identify disease-specific novel drug targets through harnessing the graph theory based network attributes.

Trusted, setuid-to-root binaries have been a substantial, long-lived source of privilege escalation vulnerabilities on Unix systems. Prior work on limiting privilege escalation has only considered privilege from the perspective of the administrator, neglecting the perspective of regular users-the primary reason for having setuid-to-root binaries.The paper presents a study of the current state of setuidto-root binaries on Linux, focusing on the 28 most commonly deployed setuid binaries in the Debian and Ubuntu distributions. This study reveals several points where Linux kernel policies and abstractions are a poor fit for the policies desired by the administrator, and root privilege is used to create point solutions. The majority of these point solutions address 8 system calls that require administrator privilege, but also export functionality required by unprivileged users. This paper demonstrates how least privilege can be achieved on modern systems for non-administrator users. We identify the policies currently encoded in setuid-to-root binaries, and present a framework for expressing and enforcing these policy categories in the kernel. Our prototype, called Protego, deprivileges over 10,000 lines of code by changing only 715 lines of Linux kernel code. Protego also adds additional utilities to keep the kernel policy synchronized with legacy, policy-relevant configuration files, such as /etc/sudoers. Although some previously-privileged binaries may require changes, Protego provides users with the same functionality as Linux and introduces acceptable performance overheads. For instance, a Linux kernel compile incurs less than 2% overhead on Protego.