CVE-2020-36432: Use of Uninitialized Resource in alg_ds

An issue was discovered in the alg_ds crate through 2020-08-25 for Rust. Matrix::new() internally calls Matrix::fill_with() which uses *ptr = value pattern to initialize the buffer. This pattern assumes that there is an initialized struct at the address and drops it, which results in dropping of uninitialized struct.