reject invalid tiff dimensions

Change-Id: I64e77f12cb016a7f4a9d21c732aaeaae7959da76
(cherry picked from commit 34d06214)
Reviewed-on: https://gerrit.libreoffice.org/17257Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>
Tested-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>

filter/source/graphicfilter/itiff/itiff.cxx

@@ -1330,6 +1330,8 @@ bool TIFFReader::ReadTIFF(SvStream & rTIFF, Graphic & rGraphic )
             }
             if ( !nBitsPerSample || ( nBitsPerSample > 32 ) )
                 bStatus = false;
+            if (nImageWidth < 0 || nImageLength < 0)
+                bStatus = false;
             if ( bStatus )
             {
                 if ( nMaxSampleValue == 0 )