Extra Padding issue on extra accounts.

[austbot]

A bug was shipped in the status instruction that pulls the first 32 bytes from the flatbuffers account struct. The bug was also featured in the node to do the same thing which allows the pubkey to incorrectly match and not error, but this added a weird byte offset that causes the pubkey to be wrong, but as stated it did not fail the on chain checks since it is doing the same thing.

Example Culprit Code

let (pkbytes, writable) = a.0.split_at(32);
let pubkey = Pubkey::try_from(pkbytes).unwrap_or_default();
AccountMeta {
    pubkey,
    is_writable: writable[0] == 1,
    is_signer: false,
}

Flat buffer schema

struct Account {
  writable: bool = false;
  pubkey: [uint8:32];
}

Since this is a struct, the byte layout is much simpler as opposed to a table, which means it looks like more like a 33 byte slice. We are grabbing the pubkey from the wrong offset 0 instead of 1.

Instead we should be using the methods to pull these fields.