Segmentation fault / stack overflow

[m00nwtchr]

I'm getting a segfault and/or stack overflow whenever I try to deserialize my data using any serde compatible library (as far as i can tell, serialization works fine), I tried ron and serde_json.

Definitions: (Should the two main files involved)

• https://github.com/m00nwtchr/cofd-miner/blob/596bca949e4fea1b2d5e989806c14b7e579abf1c/cofd-schema/src/book.rs
• https://github.com/m00nwtchr/cofd-miner/blob/596bca949e4fea1b2d5e989806c14b7e579abf1c/cofd-schema/src/item/mod.rs

Example json:

[
  {
    "info": {
      "name": "Lorem ipsum dolor sit amet",
      "shortName": "Lorem",
      "hash": "5035F594CD90296C",
      "publicationDate": "2222-09-22"
    },
    "merits": [
      {
        "name": "Lorem ipsum",
        "page": 91,
        "effects": [
          "Lorem ipsum dolor sit amet"
        ],
        "dotRating": 3,
        "prerequisites": [
          "Lorem ipsum",
          [
            "Lorem",
            3
          ]
        ]
      }
    ]
  }
]

(Not an actual sample, but I can't post that online and this still gives the error)

Example deserialization code:

use std::{fs::File, io::BufReader};

use cofd_schema::book::Book;

pub fn main() {
	let _: Vec<Book> = serde_json::from_reader(BufReader::new(
		File::open("books.json").unwrap(),
	))
	.unwrap();
}

Output:

$ cargo run --example=main
    Finished dev [unoptimized + debuginfo] target(s) in 0.09s
     Running `target/debug/examples/main`

thread 'main' has overflowed its stack
fatal runtime error: stack overflow
zsh: IOT instruction (core dumped)  cargo run --example=main

[m00nwtchr]

Oh, i found these repeating lines in the stacktrace:

#33 0x0000560e4cdef65b in serde::de::impls::{impl#197}::deserialize<cofd_schema::prerequisites::Prerequisite, serde::__private::de::content::ContentRefDeserializer<serde_json::error::Error>> (
    deserializer=...) at /home/m00n/.local/share/cargo/registry/src/index.crates.io-6f17d22bba15001f/serde-1.0.190/src/de/impls.rs:762
#34 0x0000560e4cdc4a15 in cofd_schema::prerequisites::_::{impl#0}::deserialize::{closure#0}<serde::__private::de::content::ContentRefDeserializer<serde_json::error::Error>> ()
    at /home/m00n/.local/share/cargo/git/checkouts/cofd-miner-56c4e31c2b72a1f5/961d25b/cofd-schema/src/prerequisites.rs:17
#35 0x0000560e4cdc4417 in cofd_schema::prerequisites::_::{impl#0}::deserialize<serde::__private::de::content::ContentRefDeserializer<serde_json::error::Error>> (__deserializer=...)
    at /home/m00n/.local/share/cargo/git/checkouts/cofd-miner-56c4e31c2b72a1f5/961d25b/cofd-schem/src/prerequisites.rs:17

So i guess i managed to make an endless loop 😅

[m00nwtchr]

It looks like it was the: #[serde(untagged)] attribute in combination with a variant that (via a Box) contains its own enum.

Maybe this is something that serde could catch and raise a compile time error/warning about?