* security: fallible bitmap allocation in vendored hayro-jbig2 (follow-up to #239) * security: reinitialize allocates before mutating the jbig2 bitmap (CodeRabbit)
Shared Hayro reader snapshot
The hayro, hayro-interpret, hayro-syntax and hayro-jbig2 directories are transferred
from PdfCraft revision 7437bde378f43856eada40af25b983812e615e8a.
The upstream patch ledger
describes the inherited patches. Source manifests record every transferred Git blob and
SHA-256 alongside the local hash. The source manifests themselves are not self-hashed.
The shared snapshot adds immutable per-document ordinary decode limits, threaded through initial xrefs, object streams, fallback and repair. Existing constructors retain their previous default. Known-size image budgets and streaming content budgets remain distinct. ContentReader now reports omitted or failed whole streams and incomplete Flate blocks as known incomplete content. The interpreter also reports failed or budget-reaching nested forms, patterns and Type 3 procedures. A stream exposes its immutable document limit so callers can use the same conservative completion check. This diagnostic does not cover structural repair or every omitted object and is not a rendering-completeness guarantee. The syntax manifest pins JBIG2 exactly to 0.3.0 so a newer registry release cannot bypass the transferred decoder patches. Synthetic unit tests cover these boundaries; two version tests and the introductory doctest use synthetic PDFs so they do not rely on the absent upstream corpus. No corpus is copied.
Compatibility patches follow the resource scopes and text-showing order in
Hayro 0.8.0, revision ea9c81dc70cde40c64205986fdcfcd481fe934d8,
under the same MIT OR Apache-2.0 licence. Explicit page and nested-object resource
dictionaries replace the enclosing dictionary as a whole. Missing Form resources inherit
the caller; tiling patterns use only their own resources. Direct arrays and dictionaries
are limited to 64 levels in raw and decoded content. Page-tree traversal is iterative,
retains cycle detection and inheritance, and fails closed when its 100,000-entry work
budget or a fallible frame/page allocation fails. Text-showing operations fill the
whole run before stroking it, including strings separated by adjustments in TJ.
The implementation replays bounded source operands without allocating a glyph buffer.
The existing Type 3 single-paint behavior and incomplete-content diagnostics remain.
Raw array iteration now ends safely if validation and object parsing disagree;
standalone sign tokens retain the reader's zero tolerance.
Byte transfer-function samples use rounded 8-bit values; failed or non-finite evaluations
leave the sample unchanged. Historical source hashes remain in each SOURCE.json,
alongside local hashes and the compatibility reference.
The JBIG2 segment parser caps the long-form referred-to-segment count at u16::MAX
and rejects a larger claim as an invalid count before any retention-flag or
referred-to-number bytes are consumed, so a crafted header cannot turn
Vec::with_capacity into a multi-gigabyte reservation that aborts on allocation
failure.
Hostile-input bounds (CodeRabbit findings):
- An xref-stream subsection must be backed by its decoded bytes: all-zero
/Wwidths are refused, and a declared count longer than the data is refused before any entry is inserted, so a tiny stream cannot declare billions of entries. - Each object stream's
/Nheader pairs are parsed once per document and cached beside its decoded data, instead of on every compressed-object lookup. - An embedded JBIG2 page over 2^28 pixels is refused before the output buffer is allocated,
and that buffer is reserved fallibly (
Bitmap::reinitializeallocates before touching the existing bitmap, so a failed reservation leaves it intact). AJBIG2Globalsstream with an image filter is ignored, so globals cannot recurse through further globals. - At most 4096 graphics states, holding at most 64 MiB together, are saved; a
qpast either limit is counted but not copied, and itsQstill removes the clips added since. - An xref-stream
/Wtype field wider than one byte is read at its full width (big-endian) instead of only its first byte, and/W[0]over 8 bytes is refused like/W[1]. A dash array over 256 entries strokes solid.
This remains the patched 0.7 backend. It retains the existing Bradford Lab conversion, floating component precision and codec versions, rather than claiming full 0.8 equivalence. The independent color oracles, backend tests and facade contracts cover these retained policies separately from the compatibility changes.
All other source and asset files remain unchanged. Upstream licence texts, Foxit/PDFium standard-14 fonts and the CMYK ICC profile are retained. Attribution is in the root NOTICE and ATTRIBUTION.md. The removed LAB.icc profile remains absent. Lopdf is not part of this snapshot: applications that need its editing or inspection compatibility keep owning it.
Root Cargo patch entries are required in consuming workspaces. The writer-only feature remains independent; vendoring reader sources does not make them a writer dependency.
The transferred snapshot includes the latest Lab Bradford adaptation, Type 3 rendering-mode
handling and filtered shrinking of oversized soft masks. tests/upstream_raster.rs adapts
the corresponding portable PdfCraft rendering contracts for native and WASM.
The snapshot also preserves PdfCraft #1477 (WinAnsi Unicode fallback for TrueType
fonts without Encoding) and #1499 (byte-aligned packed TIFF predictor rows).
Synthetic tests cover 1/2/4/8-bit RGB rows and rendering, plus embedded TrueType
text with absent or partial ToUnicode maps and explicit encoding precedence.