An Integrated Framework for Improving the Quality and Reliability of Software Upgrades

Despite major advances in the engineering of maintainable and robust software over the years, upgrading software remains a primitive and error-prone activity. In this dissertation, we argue that several problems with upgrading software are caused by a poor integration between upgrade deployment, testing, and problem reporting. To support this argument, we present a characterization of software upgrades resulting from a survey we conducted of 50 system administrators. Motivated by the survey results, we present Mirage, a distributed framework for integrating upgrade deployment, testing, and problem reporting into the overall upgrade development process. Mirage's deployment subsystem allows the vendor to deploy its upgrades in stages over clusters of users sharing similar environments. Staged deployment incorporates testing of the upgrade on the users' machines. It is effective in allowing the vendor to detect problems early and limit the dissemination of buggy upgrades. Oasis, the testing subsystem of Mirage, improves on current state-of-the-art concolic and symbolic engines by implementing a new heuristic to prioritize the exploration of new or affected code in the upgrade. Furthermore, interactive symbolic execution, a new approach exposing the problem of path exploration to the tester using a graphical user interface, can be used to develop new search heuristics or manually guide testing to important areas of the source code. In spite of all of these efforts, some bugs are bound to remain in the software when it is deployed, and will be discovered and reported only later by the users. With the last component of Mirage, we consider the problem of instrumenting programs to reproduce bugs effectively, while keeping user data private. In particular, we develop static and dynamic analysis techniques to minimize the amount of instrumentation, and therefore the overhead incurred by the users, while considerably speeding up debugging. By combining up-front testing, stage deployment, testing on user machines, and efficient reporting, Mirage successfully reduces the number of problems, minimizes the number of users affected, and shortens the time needed to fix remaining problems

Deux: Autonomic Testing System for Operating System Upgrades

Operating system upgrades and patches sometimes break applications that worked fine on the older version. We present an autonomic approach to testing of OS updates while minimizing downtime, usable without local regression suites or IT expertise. Deux utilizes a dual-layer virtual machine architecture, with lightweight application process checkpoint and resume across OS versions, enabling simultaneous execution of the same applications on both OS versions in different VMs. Inputs provided by ordinary users to the production old version are also fed to the new version. The old OS acts as a pseudo-oracle for the update, and application state is automatically re-cloned to continue testing after any output discrepancies (intercepted at system call level) - all transparently to users. If all differences are deemed inconsequential, then the VM roles are switched with the application state already in place. Our empirical evaluation with both LAMP and standalone applications demonstrates Deux's efficiency and effectiveness

Package upgrades in FOSS distributions: details and challenges

The upgrade problems faced by Free and Open Source Software distributions have characteristics not easily found elsewhere. We describe the structure of packages and their role in the upgrade process. We show that state of the art package managers have shortcomings inhibiting their ability to cope with frequent upgrade failures. We survey current countermeasures to such failures, argue that they are not satisfactory, and sketch alternative solutions

An implementation of the Linux software repository model for other operating systems

Year after year, the frequency of updated releases of soft-ware continues to increase. Without an automated install process, the result is either that a system installs software with known defects and/or vulnerabilities, or systems require increased manual labor to maintain up-to-date software in-stallations. Linux packages, in conjunction with repositories, fill this need for automation to reduce both undesirable situa-tions. This model can be modified to a generic operating sys-tem environment, such as Windows, which currently lacks the capability to update arbitrary software applications. Our application, Appupdater, demonstrates this concept of de-tecting, downloading, and installing upgrades automatically. This provides a completely automated upgrade cycle

Aeronautical engineering: A continuing bibliography with indexes (supplement 278)

This bibliography lists 414 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1992

Hypertracing: Tracing through virtualization layers

Cloud computing enables on-demand access to remote computing resources. It provides dynamic scalability and elasticity with a low upfront cost. As the adoption of this computing model is rapidly growing, this increases the system complexity, since virtual machines (VMs) running on multiple virtualization layers become very difficult to monitor without interfering with their performance. In this paper, we present hypertracing, a novel method for tracing VMs by using various paravirtualization techniques, enabling efficient monitoring across virtualization boundaries. Hypertracing is a monitoring infrastructure that facilitates seamless trace sharing among host and guests. Our toolchain can detect latencies and their root causes within VMs, even for boot-up and shutdown sequences, whereas existing tools fail to handle these cases. We propose a new hypervisor optimization, for handling efficient nested paravirtualization, which allows hypertracing to be enabled in any nested environment without triggering VM exit multiplication. This is a significant improvement over current monitoring tools, with their large I/O overhead associated with activating monitoring within each virtualization layer

But is it exploitable? Exploring how Router Vendors Manage and Patch Security Vulnerabilities in Consumer-Grade Routers

Millions of consumer-grade routers are vulnerable to security attacks. Router network attacks are dangerous and infections, presenting a serious security threat. They account for 80% of infected devices in the market, posing a greater threat than infected IoT devices and desktop computers. Routers offer an attractive target of attacks due to their gateway function to home networks, internet accessibility, and higher likelihood of having vulnerabilities. A major problem with these routers is their unpatched and unaddressed security vulnerabilities. Reports show that 30% of critical router vulnerabilities discovered in 2021 have not received any response from vendors. Why? To better understand how router vendors manage and patch vulnerabilities in consumer-grade routers, and the accompanying challenges, we conducted 30 semi-structured interviews with professionals in router vendor companies selling broadband and retail routers in the UK. We found that router professionals prioritize vulnerability patching based on customer impact rather than vulnerability severity score. However, they experienced obstacles in patching vulnerabilities due to outsourcing development to third parties and the inability to support outdated models. To address these challenges, they developed workarounds such as offering replacement routers and releasing security advisories. However, they received pushback from customers who were not technically capable or concerned about security. Based on our results, we concluded with recommendations to improve security practice in routers