An issue was discovered in the lexer crate through 2020-11-10 for Rust. For ReaderResult<T, E>, there is an implementation of Sync with a trait bound of T: Send, E: Send.

Affected: crates.io: lexer

lexer is a plugin based lexical reader.Affected versions of this crate implements Sync for ReaderResult<T, E> with the trait bound T: Send, E: Send. Since matching on the public enum ReaderResult<T, E> provides access to &T & &E, allowing data race to a non-Sync type T or E. This can result in a memory corruption when multiple threads concurrently access &T or &E. Suggested fix for the bug is change the trait bounds imposed on T & E to be T: Sync, E: Sync.

Affected: crates.io: lexer

Affected versions of this crate implements `Sync` for `ReaderResult<T, E>` with the trait bound `T: Send, E: Send`.

Since matching on the public enum `ReaderResult<T, E>` provides access to `&T` & `&E`, allowing data race to a non-Sync type `T` or `E`. This can result in a memory corruption when multiple threads concurrently access `&T` or `&E`.

Suggested fix for the bug is change the trait bounds imposed on `T` & `E` to be `T: Sync, E: Sync`.