Title
Secure virtual architecture: a safe execution environment for commodity operating systems
Abstract
This paper describes an efficient and robust approach to provide a safe execution environment for an entire operating system, such as Linux, and all its applications. The approach, which we call Secure Virtual Architecture (SVA), defines a virtual, low-level, typed instruction set suitable for executing all code on a system, including kernel and application code. SVA code is translated for execution by a virtual machine transparently, offline or online. SVA aims to enforce fine-grained (object level) memory safety, control-flow integrity, type safety for a subset of objects, and sound analysis. A virtual machine implementing SVA achieves these goals by using a novel approach that exploits properties of existing memory pools in the kernel and by preserving the kernel's explicit control over memory, including custom allocators and explicit deallocation. Furthermore, the safety properties can be encoded compactly as extensions to the SVA type system, allowing the (complex) safety checking compiler to be outside the trusted computing base. SVA also defines a set of OS interface operations that abstract all privileged hardware instructions, allowing the virtual machine to monitor all privileged operations and control the physical resources on a given hardware platform. We have ported the Linux kernel to SVA, treating it as a new architecture, and made only minimal code changes (less than 300 lines of code) to the machine-independent parts of the kernel and device drivers. SVA is able to prevent 4 out of 5 memory safety exploits previously reported for the Linux 2.4.22 kernel for which exploit code is available, and would prevent the fifth one simply by compiling an additional kernel library.
Year
DOI
Venue
2007
10.1145/1294261.1294295
SOSP
Keywords
Field
DocType
type system,security,memory safety,operating systems,trusted computing base,compiler,virtual machine,type safety,operating system,lines of code
Memory safety,Virtual machine,sysfs,Computer science,Configfs,Trusted computing base,Operating system,Kernel virtual address space,Source lines of code,Linux kernel,Embedded system
Conference
Volume
Issue
ISSN
41
6
0163-5980
Citations 
PageRank 
References 
76
4.05
25
Authors
4
Name
Order
Citations
PageRank
John Criswell141219.95
Andrew Lenharth245619.94
Dinakar Dhurjati348727.35
Vikram S. Adve43347183.25