sanity check ScanlineInput bytesPerLine instead of lineOffset size (A…

…cademySoftwareFoundation#863) Signed-off-by: Peter Hillman <[email protected]> Co-authored-by: Cary Phillips <[email protected]> Signed-off-by: Cary Phillips <[email protected]>
cary-ilm · May 12, 2021 · 1109037 · 1109037
1 parent e4c637c
commit 1109037
Showing 1 changed file with 27 additions and 0 deletions.
diff --git a/OpenEXR/IlmImf/ImfScanLineInputFile.cpp b/OpenEXR/IlmImf/ImfScanLineInputFile.cpp
@@ -1108,6 +1108,33 @@ void ScanLineInputFile::initialize(const Header& header)
         _data->minY = dataWindow.min.y;
         _data->maxY = dataWindow.max.y;
 
+        Compression comp = _data->header.compression();
+
+        _data->linesInBuffer =
+            numLinesInBuffer (comp);
+
+        int lineOffsetSize = (dataWindow.max.y - dataWindow.min.y +
+                              _data->linesInBuffer) / _data->linesInBuffer;
+
+        //
+        // avoid allocating excessive memory due to large lineOffsets and bytesPerLine table sizes.
+        // If the chunktablesize claims to be large,
+        // check the file is big enough to contain the lineOffsets table before allocating memory
+        // in the bytesPerLineTable and the lineOffsets table.
+        // Attempt to read the last entry in the table. Either the seekg() or the read()
+        // call will throw an exception if the file is too small to contain the table
+        //
+        if (lineOffsetSize * _data->linesInBuffer > gLargeChunkTableSize)
+        {
+            Int64 pos = _streamData->is->tellg();
+            _streamData->is->seekg(pos + (lineOffsetSize-1)*sizeof(Int64));
+            Int64 temp;
+            OPENEXR_IMF_INTERNAL_NAMESPACE::Xdr::read <OPENEXR_IMF_INTERNAL_NAMESPACE::StreamIO> (*_streamData->is, temp);
+            _streamData->is->seekg(pos);
+
+        }
+
+
         size_t maxBytesPerLine = bytesPerLineTable (_data->header,
                                                     _data->bytesPerLine);