Add unsound advisory for hibit_tree

[tooson9010-spec]

Affected crate(s)

• hibit_tree (123 recent downloads per crates.io)

Links to upstream issue(s) or PR(s)

tower120/hibit_tree#28

Severity

BlockPtr::insert_impl set the occupancy bit in mask before running the child constructor and wrote the index mapping only afterwards, so a panicking Default::default() left the two halves of the metadata disagreeing — two logical indices resolved to the same physical slot and Drop for Tree destroyed it twice. Use-after-free / double-free reachable from safe Rust via Tree::get_or_insert, confirmed under AddressSanitizer. Fixed in 0.1.1-beta.1.

Checklist

• Advisory filename(s) starts with RUSTSEC-0000-0000 as the ID
• date field is set to the public disclosure date
• Contains a concise and descriptive title after advisory metadata
• Asked maintainer(s) if publishing an advisory is appropriate (asked on the PR; the maintainer responded by releasing the fix as 0.1.1-beta.1)