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[AAT] Fully sanitize ankr table at sanitize time 

Third try to fix access. Followup 6879efc2c1

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12532
Fixes https://bugs.chromium.org/p/chromium/issues/detail?id=922303
This commit is contained in:
Behdad Esfahbod 2019-01-17 14:54:32 -05:00
parent 6879efc2c1
commit cc8e9a436f
1 changed files with 4 additions and 9 deletions
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13
src/hb-aat-layout-ankr-table.hh
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@ -65,14 +65,10 @@ struct ankr
unsigned int num_glyphs,
const char *end) const
{
const Offset<HBUINT16, false> *offset = (this+lookupTable).get_value (glyph_id, num_glyphs);
const OffsetTo<GlyphAnchors, HBUINT16, false> *offset = (this+lookupTable).get_value (glyph_id, num_glyphs);
if (!offset)
return Null(Anchor);
const GlyphAnchors &anchors = StructAtOffset<GlyphAnchors> (&(this+anchorData), *offset);
if (unlikely (end < (const char *) &anchors ||
end - (const char *) &anchors < anchors.len.static_size ||
end - (const char *) &anchors < anchors.get_size ()))
return Null(Anchor);
const GlyphAnchors &anchors = &(this+anchorData) + *offset;
return anchors[i];
}
@ -81,14 +77,13 @@ struct ankr
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
version == 0 &&
lookupTable.sanitize (c, this) &&
anchorData.sanitize (c, this) /* Just one byte. */));
lookupTable.sanitize (c, this, &(this+anchorData))));
}
protected:
HBUINT16 version; /* Version number (set to zero) */
HBUINT16 flags; /* Flags (currently unused; set to zero) */
LOffsetTo<Lookup<Offset<HBUINT16, false> >, false>
LOffsetTo<Lookup<OffsetTo<GlyphAnchors, HBUINT16, false> >, false>
lookupTable; /* Offset to the table's lookup table */
LOffsetTo<HBUINT8, false>
anchorData; /* Offset to the glyph data table */