RUSTSEC-2023-0017 (unsound) on 2023-03-04: maligned::align_first causes incorrect deallocation

maligned::align_first manually allocates with an alignment larger than T, and then uses Vec::from_raw_parts on that allocation to get a Vec<T>.

GlobalAlloc::dealloc requires that the layout argument must be the same layout that was used to allocate that block of memory.

When deallocating, Box and Vec may not respect the specified alignment and can cause undefined behavior.


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0.2.1 (current) Rating: Negative + Unmaintained Thoroughness: None Understanding: None

by on 2022-04-08

Functions whose name starts with align_first are unsound as they create allocations whose alignment doesn't match the alignment of an allocation. This can cause hard to debug issues when using alignment aware allocator.

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To review the actual code of the crate, it's best to use cargo crev open maligned. Alternatively, you can download the tarball of maligned v0.2.1 or view the source online.