Multiple memory safety vulnerabilities

[vnrst]

There are multiple memory safety issues with the implementations of methods in CMutSlice that are marked safe, allowing aliased mutable references.

For example :

extern crate cslice;
use cslice::{CMutSlice};

fn main() {
	let mut a : [i32; 5] = [1, 2, 3, 4, 5];

	let mut sl = unsafe{CMutSlice::new(&mut a[0], 5)};

	// Multiple mutable references to same location
	let ptr1: &mut[i32] = sl.as_mut_slice();
	let ptr2: &mut[i32] = sl.as_mut_slice();

	ptr1[0] = 5;

	println!("{:?}", ptr2); // ptr2 will have also changed
}

Similarly, one could exploit vulnerabilities in CMutSlice::as_ptr() and CMutSlice::clone (implicitly derived).