3 * size_of::<usize> because of metadata write operations.Heap::extend with a size smaller than two usizes (e.g., 16 on x86_64), the size was erroneously rounded up to the minimum size, which could result in an out-of-bounds write.Heap::extend on an empty heap tried to construct a heap starting at address 0, which is also an out-of-bounds write.
Heap::new (or a similar constructor) with a heap size that is smaller than two usizes. This was treated as an empty heap as well.Heap::extend on a heap whose size is not a multiple of the size of two usizes resulted in unaligned writes. It also left the heap in an unexpected state, which might lead to subsequent issues. We did not find a way to exploit this undefined behavior yet (apart from DoS on platforms that fault on unaligned writes).{
"license": "CC0-1.0"
}