What is Memory Safety?

Memory safety is a critical concept in computer programming that ensures programs access memory locations securely and correctly. It prevents errors like buffer overflows, use-after-free, and other vulnerabilities that malicious actors can exploit to compromise systems. All too often this fails, often because of inherited code that was not specificed for the specific application.

Why Does Memory Safety Matter?

Memory safety is critical in every digitial system because the consequences are pernicious, widespread, and all to often invisable, even to the best software developers and tools.

Security: Memory-related vulnerabilities, such as buffer overflows, are a common target for hackers. By enforcing memory safety, systems become resistant to many attacks.

Stability: Software errors related to memory usage can cause crashes, data corruption, or unexpected behavior.

Reliability: Systems with strong memory safety guarantees reduce the risk of bugs and increase the overall reliability of applications, especially in critical systems like automotive, defense, and medical devices.

How Do Memory Safety Issues Arise?

Memory safety issues often come from incorrect handling of pointers or references to memory, particularly in low-level languages like C or C++. Some common causes include:

Buffer Overflows: When a program writes more data to a buffer (a temporary storage space) than it can hold, it can overwrite adjacent memory.

Dangling Pointers: This occurs when a pointer references memory that has already been freed or is no longer valid.

Use-After-Free: Accessing memory after it has been freed can lead to unpredictable behavior.

How is Memory Safety Achieved?

Memory safety has been attempted in several ways, including:

Formal Methods: Tightly defined specifications and interfaces and rigorous testing is the most traditional approach to Memory Safety, but the costs are often too high, and code reuse too low to make this aceptable in most application development.

Automatic Memory Management: Garbage-collected languages like Java, Python, and C# automatically manage memory allocation and deallocation, reducing the risk of memory-related bugs.

Safe Programming Languages: Languages like Rust and Swift have built-in memory safety features that attempt to prevent developers from making common memory management errors.

Static Analysis and Runtime Checks: These tools analyze code for potential memory safety violations, ensuring that unsafe memory operations are detected before or during execution.

CHERI Architecture: CHERI (Capability Hardware Enhanced RISC Instructions) extends existing hardware to provide fine-grained memory protection at the instruction level. CHERI-based processors like those being developed at SCI Semiconductor offer hardware-enforced memory safety by using capabilities that track the boundaries and permissions of every memory reference.

Real-World Examples of Memory Safety

Memory safety is vital in industries where software reliability is crucial:

Critical Infrastructure: As we enter a new cold-war based on cyber resilience more and more critical infrastructure system, such as energy distribution, water treatment and transportation systems become vulnerable to widespread attack - potentially paralysing cities and even nations. 

Automotive: Embedded systems in cars must be reliable, especially in autonomous driving. Memory errors could lead to catastrophic failures.

Medical Devices: A memory error in a medical device, such as a pacemaker, could result in life-threatening consequences.

Defense: Security is paramount in defense systems, and memory safety ensures that systems remain robust and resistant to attack.

How SCI Semiconductor is Bringing Memory Safety to Hardware

At SCI Semiconductor, we are at the forefront of bringing hardware-enforced memory safety to critical industries. Our microcontrollers and processors, designed with CHERI-based technology, offer unprecedented levels of security and reliability by eliminating the most common types of memory vulnerabilities.

We are collaborating with industry leaders like Microsoft and Google, as well as the UK and US governments, to drive this cutting-edge technology to market. Our products, launching in 2025, will provide a new standard in secure computing for critical infrastructure, defense, automotive, and medical markets.