Chunk::{clear, drop left, drop right} and InlineArray::{clear, truncate} drop the removed elements before updating the metadata that records which slots hold live values — the left/right index pair for Chunk, the length field for InlineArray. If an element's Drop panics during the drop, that update is never reached, so the collection still treats the already-dropped elements as live. When the collection is later dropped (its destructor walks the range described by the stale metadata), or a subsequent operation touches the same slots, those elements are dropped a second time — a double free (CWE-415) / use-after-free (CWE-416) reachable from safe Rust.

The stale field is left and right for Chunk::clear, left for drop left, right for drop right, and the length field for both InlineArray methods.

Upgrade to imbl-sized-chunks 0.2.0 or later, which commits the metadata before dropping any element (fixed in jneem/imbl-sized-chunks#14, released in 0.2.0).