feat: parser safety nets — multi-array validation + input-size cap - #3
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…input The variable_array_sane? check (added in PR #2) covered POLYGON/POLYLINE/ POLYBEZIER/POLYBEZIERTO/POLYLINETO + their 16-bit variants + POLYDRAW/16. This commit extends the check to multi-array records: - POLYPOLYGON, POLYPOLYLINE, POLYPOLYGON16, POLYPOLYLINE16: each has TWO variable arrays (aPolyCounts and aptl/apts). Both counts are now validated against nSize before bindata tries to allocate. Adds MAX_INPUT_BYTES = 200 MB guard at the parser entry point. Refuses inputs larger than 200 MB before any allocation. The 5.7 MB EMF fixture in the corpus is large; 200 MB is a generous safety margin.
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feat: parser safety nets — multi-array validation + input-size cap
The
variable_array_sane?check introduced in PR #2 covered thecommon single-array records (POLYGON, POLYLINE, POLYBEZIER, POLYDRAW,
etc.). This commit closes two remaining pathological-allocation
vectors.
What it does
Extends array sanity check to multi-array records.
POLYPOLYGON,POLYPOLYLINE,POLYPOLYGON16,POLYPOLYLINE16each carry TWO variable-length arrays:
aPolyCounts(
nPolysuint32s) andaptl/apts(cTotalentries). Previouslyonly the second array was validated; corrupt first-array counts
could still trigger massive allocations.
nSizebefore bindataattempts to allocate.
Adds a global input-size cap.
MAX_INPUT_BYTES = 200 MBenforced at the parser entry point.Emf::FormatErrorimmediately, before anyallocation.
Why it matters
The original
cpts=41026074hang in PR #2 came from a single-arrayrecord. The same class of bug exists for the multi-array records —
the parser is now safe against pathological inputs from any source
(corrupt fixtures, hostile callers, accidental
wc -coutputs).Verification
emf-corrupted/files still parse without crashing or hanging.parsing begins.