2026-09-26 17:42:16 +00:00
1 changed files with 15 additions and 0 deletions
@@ -21,6 +21,21 @@
  python-blosc2 4.13.1 for what hdf5plugin never writes
  (`crates/clawhdf5-format/tests/fixtures/blosc2/`); the decoder is
  fuzzed. Conformance: 576 of 697 files ok (was 575) — h5ex_d_blosc2.
 - **A crafted Blosc2 chunk cannot allocate more than a few times its HDF5
  chunk size.** Found in review before release: the sizes a frame declares
  sized the decoder's buffers. A 173-byte frame whose offsets chunk claimed
  2 GiB was decoded in full for a 1 MiB chunk; an empty chunk allocated its
  declared block size twice (about 1 GiB); a B2ND chunk was decoded whole
  with its padding (up to 16x the chunk); and a Zstandard stream's declared
  window (up to 100 MiB) was reserved as the decoder was reused, which also
  affected Blosc 1 and bitshuffle with Zstandard. Now the offsets chunk is
  capped at the chunk size, block sizes are clamped to the chunk, B2ND
  blocks are placed as they are decoded (padding is never held), and the
  Zstandard window is capped at twice the stream's output (at least
  128 KiB). A B2ND chunk may no longer be larger than its array, which
  hdf5-blosc2 never writes. `tests/blosc2_alloc_bounds.rs` measures peak
  allocation for these frames and for 45,000 fuzzed ones: at most 6x the
  chunk size, twice the input and 2 MiB of Zstandard state.
 ### Concurrent reads (2026-09-26)
 - **Full reads of chunked datasets scale with threads again when rayon's