* Never crash: decompression bombs can't exhaust the renderer's memory
The renderer's parser (vendored hayro-syntax) decoded Flate, LZW and
RunLength streams with no output limit. A 2 MB page whose content
stream inflates to 2 GB, or whose 8 x 8 image does, took `pdfcraft-cli
render` and `text` past 3 GB in under a second, and a few more MB of
file scale it further. On the desktop that is the first-page render of
an emailed PDF, and the allocation-failure abort takes every open
document with it. Our own layers already bound single streams (lopdf's
load-time decoding at 256 MiB, cos at 1 GiB), so `info` stays at a few
MB; the renderer path didn't. Random mutation almost never makes a
high-ratio stream, so `cargo xtask fuzz` doesn't find this; found by
hand while triaging the fuzz run.
Vendored hayro-syntax patch (6):
- `decode_limit` gives each filter an output limit, and Flate (both
flate2 and the fallback inflater), LZW and RunLength never write past
it (the buffer can still grow to under twice it):
`MAX_DECODED_STREAM`, 256 MiB, lopdf's figure; or, for the last filter
of an image whose size, bits per component and components are known,
twice its pixel bytes (a PNG predictor tag byte per byte at most),
capped at 1 GiB. Earlier filters in a chain produce compressed data
and get the general limit.
- `Stream::decoded_within(max)` for callers that budget.
- A page's `/Contents` array shares one `MAX_DECODED_STREAM` (naming one
bomb twenty times decoded 5 GB), reserving exactly what it appends.
Vendored hayro-interpret patch (18):
- The content a page holds at once (its contents, and the forms, tiling
patterns and Type 3 glyph procedures being painted) stays within
`MAX_PAGE_CONTENT`, 512 MiB, reset per page like the existing paint
budget. Forms nest fifty deep and each level kept its content while
the next ran: a form painting itself around a 256 MiB stream would
have held over 12 GB. Each level gives its bytes back when it is
dropped, so content painted again and again keeps drawing, and a
stream without filters (borrowed from the file) costs nothing.
- Type 0 sampled functions read every sample into a 4-byte value and
then a table entry: 256 MiB of 1-bit samples asked for over 8 GB. They
now take at most 2^21 table points and 2^23 values (the largest real
tables, DeviceN tint transforms such as 33^4 points x 3 outputs, are
1.2 million and 3.6 million), counted with checked arithmetic, and
read no further than `/Size` asks. `/Size 0` no longer underflows
building the default `/Encode`.
Three rounds of independent review found the aggregate cases, buffer
doubling past the limit, a chain/predictor shape the first image limit
would have truncated, the Type 0 amplifier, and a first, cumulative
budget that would have dropped legitimately repeated content, and a
first Type 0 cap low enough to refuse real tint transforms; all fixed
here.
Measured in a release build (render; OS peak commit):
- content stream inflating to 2 GB: 389 MB, 0.3 s
- 8 x 8 image inflating to 2 GB: 4 MB, 0.2 s
- /Contents naming it twenty times: 516 MB, 0.3 s
- a form painting itself around it: 644 MB, 0.4 s
Synthetic regression tests in render (flate2 is a new dev-dependency
there, already in the workspace):
- `decompression_bombs_stop_at_the_stream_limit`: 288 MiB bombs through
flate2, the fallback inflater (a stored block with a wrong length
check, which flate2 refuses and the fallback accepts), LZW and
RunLength each decode exactly 256 MiB, and at most 128 bytes as an
8 x 8 image.
- `page_contents_and_nested_forms_share_one_budget`: three /Contents
references decode one stream's worth; a self-painting form finishes.
- `content_painted_again_and_again_keeps_drawing`: a 2 MiB form painted
300 times draws the 300th time.
- `sampled_functions_with_billions_of_samples_are_refused`.
Ten mutations each turn them red: no limit at all; no limit in flate2,
the fallback, LZW, RunLength or for images; an unshared /Contents limit;
no page budget; no refund on drop; no Type 0 sample cap. (Taking a form
out of the budget no longer compiles: its content is the budget guard.)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* M2: normalize JPEG2000 samples without overflowing
Use bounded integer sample scaling for 1-32-bit JPX images and reject empty dimensions before chunking. Cover public decoding and continued page rendering with synthetic regressions.
Co-Authored-By: OpenAI Codex <codex@openai.com>
* Never crash: decompression cut at its limit is logged, not silent; vendor README renumbered after #575
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Streetblock <github@streetblock.de>
Co-authored-by: OpenAI Codex <codex@openai.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
* M2: normalize JPEG2000 samples without overflowing
Use bounded integer sample scaling for 1-32-bit JPX images and reject empty dimensions before chunking. Cover public decoding and continued page rendering with synthetic regressions.
Co-Authored-By: OpenAI Codex <codex@openai.com>
* ROADMAP: keep the JPX entry with this session's entries
---------
Co-authored-by: OpenAI Codex <codex@openai.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
hayro-syntax recovered a stream with a wrong /Length by scanning ahead
for the bytes `stream`. An indirect appearance-state dictionary
(`<< /Yes … /Off … >>`, as Quartz writes a checkbox's `/AP /N`) was
read as whatever stream came later in the file. That dictionary has no
`/BBox`, so the appearance was dropped and the widget was skipped.
`stream` now has to be the next token. A wrong `/Length` still
recovers, and the renderer already selects the `/AS` state once `/N`
is a dictionary.
Fixes#180
Co-authored-by: Eri Bastos <eb@fluxmail.xyz>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
The app, crates, binaries, bundle id, packaging, icons, screenshots and docs are now
PdfCraft / pdfcraft (repo storytold/pdfcraft). On first launch the desktop app moves the
PrintCraft settings and crash-recovery folders to the new name, and both apps read settings
saved under the old storage key, so upgrades keep recent files, preferences and unsaved work.
The signing test fixtures keep their PrintCraft subject names (they are binary).
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Every hang the nightly fuzz job found (11 findings, 8 source files) now
finishes in 0.1-2 s; each cause has a synthetic regression test that times
out without its fix.
- cos (7 findings, our own parser): a stream whose /Length pointed at
itself, with no endstream, made every parse attempt fail and each attempt
reload the same object: ~2^32 parses. Objects being loaded are a seen-set,
/Length values are memoised per load, and the shifted-header retry only
runs when the header is shifted.
- hayro-syntax (3): deciding where an inline image's data ends re-parsed the
rest of the stream, nesting through every inline image; 50 images ran for
over ten minutes. The look-ahead no longer nests and is bounded (256).
- hayro-interpret (1): a Type 3 glyph showing eight glyphs of its own font,
sixteen deep. Nested paints share a per-page budget (50,000).
The pdf.js corpus sweep matches its baseline (963 ok, same 20 known).
xtask check writes its report under CARGO_TARGET_DIR too.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The second full nightly fuzz run on main found two more:
- hayro-syntax computed a Flate/LZW predictor row as columns × bits in
wrapping arithmetic: /Columns 9223372036854775807 asked for 2^61 bytes and
aborted on any machine. Row widths are now saturating usize (colors × bits
also overflowed u8), a zero width is refused (it divided by zero), and a
row longer than the data is not allocated (empty output, as before).
- hayro stroked /LW 9223372036854775807 as given, and stroke expansion
allocated 10 GB. Widths are clamped to 4 × (canvas width + height) device
pixels, which covers the same pixels.
Both findings now run in 8 MB. Synthetic regression test in render.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The first full nightly fuzz run on main (now that the runner survives) found
two 4 GiB allocations, caught by the 4 GiB child cap:
- an inline stencil mask claiming /W 4294967295 was decoded in hayro-interpret
before the renderer's MAX_IMAGE_PIXELS check could skip it (locally 9.6 GB,
42 s). Vendored patch image_size_ok: images and masks over 2^28 pixels are
not decoded.
- a CCITT image whose /DecodeParms claimed /Columns 4294967295 (with a small
/Width) sized the decoder's line buffers (locally 4.3 GB). Vendored patch
ccitt_size_ok in hayro-syntax: at most 2^20 columns and 2^28 pixels.
Both findings now run in 7 MB. Synthetic regression test in render.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
