Explain Buffer overflow in Rust with example.

Buffer overflow is a common type of vulnerability that occurs when a program writes data beyond the boundaries of a buffer, leading to memory corruption and potential security issues. However, Rust's memory safety guarantees and ownership system help prevent buffer overflows by detecting and preventing such errors at compile-time. Rust's string handling and array bounds checking provide built-in protection against buffer overflows.

Here's an example of how Rust mitigates buffer overflow:

fn main() {
    let mut buffer = [0u8; 4]; // Buffer of size 4

    let data = [1u8, 2u8, 3u8, 4u8, 5u8]; // Data larger than buffer size

    // Uncommenting the line below would result in a compilation error.
    // buffer.copy_from_slice(&data); // Attempt to write data into buffer

    println!("Buffer: {:?}", buffer);
} 

In this example, we have a fixed-size buffer with a capacity of 4 bytes ([0u8; 4]) and a data array (data) with a length of 5 bytes. The intention is to copy the contents of the data array into the buffer using the copy_from_slice method. However, if we try to compile this code as it is, the Rust compiler will raise a compilation error. 

The compilation error occurs because Rust's copy_from_slice method performs bounds checking to ensure that the destination buffer (in this case, buffer) has enough capacity to hold the data being copied. Since the buffer has a capacity of 4 bytes and the data array has a length of 5 bytes, the copy operation would exceed the buffer's bounds and potentially lead to a buffer overflow. 

Rust's type and memory safety guarantees ensure that such buffer overflows are caught and reported at compile-time, preventing the corresponding runtime errors and security vulnerabilities. The compiler enforces strict checks on array accesses and ensures that data is stored safely within the bounds of allocated memory. 

 It's important to note that while Rust protects against buffer overflows through compile-time checks, it's still crucial for developers to practice good coding habits and adhere to Rust's memory management principles. By following Rust's ownership, borrowing, and slice handling rules, developers can further enhance the safety and security of their code, avoiding common vulnerabilities like buffer overflows.