Research on Heap Security Mechanism Based on Block Randomization

C/C++ languages often require dynamically man-aged temporary memory, i.e. heap memory, however securing heap memory is very challenging. Attacks like heap overflow, use-after-free, invalid-free, and double-free are very common, and these attacks can corrupt user data in heap memory, such as overwriting variable pointers, function pointers, and data to construct arbitrary memory reads and writes, as well as control flow hijacking. Despite the extensive research in the area of heap memory security, many modern software still suffers from such vulnerabilities. Therefore, the security of the heap region of a program is a growing concern, and the study of heap region security can help mitigate the negative impact of the increasing number of heap security vulnerabilities, which is of great practical significance. One of the major reasons that make the heap vulnerable is that the addresses of heap blocks are predictable in advance, because the allocation of heap space is too regular. In this paper, we propose a block randomization algorithm for the entire heap memory space. The algorithm proposes a random memory block allocation method that increases the unpredictability of the heap memory address and improves the security of the computer system, and at the end, the defense effect as well as the performance of the algorithm is tested through experiments to determine the optimal randomization parameters.