Stack-based memory corruption vulnerabilities have been exploited, allowing attackers to execute arbitrary code and read/write arbitrary memory. Although several solutions have been proposed to prevent memory errors on the stack, they are either limited to a specific type of attack (either spatial or temporal attacks) or cause significant performance degradation. In this article, we introduce SaVioR, an efficient and comprehensive stack protection mechanism. The key technique involves randomization of the stack layout to reduce its predictability and exploitability. SaVioR isolates an individual object from spatially and temporally adjacent vulnerable objects and randomizes each object's location, which prevents attackers from predicting the stack layout and thus reduces the likelihood of memory errors being exploited. We implemented SaVioR based on the LLVM compiler framework and applied it to the SPEC CPU2006 benchmarks and real-world applications. Our security evaluation showed that SaVioR provides a high degree of randomness in the stack layout and thus reduces the likelihood of successful exploitation of spatial and temporal memory errors on the stack. Our performance evaluation also demonstrated that it incurs a modest performance overhead (14 percent) with the SPEC CPU2006 benchmark suite, which improves performance compared to the state-of-the-art stack protection while achieving a comparable security level.

ARM TrustZone is widely used to provide a Trusted Execution Environment (TEE) for mobile devices. However, the use of TrustZone is limited because TrustZone resources are only available for some pre-authorized applications. In other words, only alliances of the TrustZone OS vendors and device manufacturers can use TrustZone to secure their services. To help overcome this problem, we designed the PrivateZone framework to enable individual developers to utilize TrustZone resources. Using PrivateZone, developers can run Security Critical Logics (SCL) in a Private Execution Environment (PrEE). The advantage of PrivateZone is its leveraging of TrustZone resources without undermining the security of existing services in the TEE. To guarantee this, PrivateZone creates a PrEE using a memory region that is isolated from both the Rich Execution Environment (REE) and TEE. In this paper, we describe the design and implementation of PrivateZone. The prototype of PrivateZone was implemented on an Arndale board with a Cortex-A15 dual-core processor. We built PrivateZone by exploring both security and virtualization extensions of the ARM architecture. To illustrate the usage and the efficacy of PrivateZone, we developed an Android application based on PrivateZone framework, and evaluated the performance overhead imposed on the OS in the REE and SCLs in the PrEE.