Slice index out of bounds when parsing upcase table for malformed FS

[5225225]

fn main() {
    let data = [
        235, 82, 144, 78, 84, 70, 83, 32, 32, 0, 0, 0, 0, 0, 0, 128, 32, 128, 0, 255, 15, 0, 0, 0,
        0, 0, 0, 32, 0, 0, 0, 0, 0, 0, 0, 255, 7, 0, 0, 0, 0, 0, 0, 149, 0, 0, 0, 8, 0, 0, 0, 120,
        183, 16, 124, 224, 39, 74, 127, 0, 0, 0, 0, 14, 31, 190, 113, 124, 172, 34, 192, 116, 11,
        86, 180, 14, 187, 7, 0, 205, 16, 94, 235, 240, 50, 228, 205, 22, 205, 25, 235, 254, 84,
        104, 105, 115, 32, 105, 115, 32, 110, 111, 116, 32, 97, 32, 98, 111, 111, 116, 97, 98, 108,
        101, 32, 100, 105, 115, 107, 46, 32, 80, 50, 101, 97, 115, 101, 32, 105, 110, 115, 101,
        114, 116, 32, 97, 32, 98, 111, 111, 116, 97, 98, 108, 101, 32, 102, 108, 111, 112, 112,
        121, 32, 97, 110, 100, 13, 10, 112, 114, 101, 115, 115, 32, 97, 110, 121, 32, 107, 101,
        121, 32, 116, 111, 32, 116, 114, 121, 32, 97, 103, 97, 105, 110, 32, 97, 110, 121, 32, 107,
        101, 121, 32, 116, 111, 32, 116, 114, 121, 32, 97, 103, 97, 105, 110, 32, 46, 46, 46, 32,
        13, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 255,
        255, 255, 255, 2, 183, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 128, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 85, 170,
    ];
    let mut data = std::io::Cursor::new(data);
    let mut fs = ntfs::Ntfs::new(&mut data).unwrap();
    fs.read_upcase_table(&mut data);
}

Error: thread 'main' panicked at 'range end index 4 out of range for slice of length 0', /home/jess/.cargo/registry/src/github.com-1ecc6299db9ec823/ntfs-0.1.0/src/record.rs:108:9

[ColinFinck]

FYI, I didn't forget about your report, thanks for opening it!

I implemented some parts like NtfsFile::new infallible when earlier called code should have indeed checked that the used sizes are reasonable. I initially didn't handle the case when a malformed filesystem reports zero sizes, but this has been fixed by d3fcffd.
In one of the next commits, I want to tighten the record and sector sizes even more to reasonable limits to combat OOM situations. While working on that, I also found larger cluster sizes to require slightly different handling in index records, which I also want to tackle.

All of this taken together should make malformed filesystems bail out early and thereby fix this bug.