Fix infinite loop caused when the end of the stream is reached (#577)

dotnet · Jun 5, 2020 · c2eb0c0 · c2eb0c0
1 parent cd38e39
commit c2eb0c0
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SslOverTdsStream.cs b/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SslOverTdsStream.cs
@@ -104,9 +104,16 @@ private async Task<int> ReadInternal(byte[] buffer, int offset, int count, Cance
                     // Account for split packets
                     while (readBytes < TdsEnums.HEADER_LEN)
                     {
-                        readBytes += async ?
+                        var readBytesForHeader = async ?
                             await _stream.ReadAsync(packetData, readBytes, TdsEnums.HEADER_LEN - readBytes, token).ConfigureAwait(false) :
                             _stream.Read(packetData, readBytes, TdsEnums.HEADER_LEN - readBytes);
+
+                        if (readBytesForHeader == 0)
+                        {
+                            throw new EndOfStreamException("End of stream reached");
+                        }
+
+                        readBytes += readBytesForHeader;
                     }
 
                     _packetBytes = (packetData[TdsEnums.HEADER_LEN_FIELD_OFFSET] << 8) | packetData[TdsEnums.HEADER_LEN_FIELD_OFFSET + 1];