ofz#52685 Timeout

only allow a short read after reading the preamble of the tiff

Change-Id: Idd4b8892457566daa028c68125fe3beeb7499803
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/142346
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/vcl/source/filter/itiff/itiff.cxx b/vcl/source/filter/itiff/itiff.cxx
index 510261e21b91..3e308f3019d3 100644
--- a/vcl/source/filter/itiff/itiff.cxx
+++ b/vcl/source/filter/itiff/itiff.cxx
@@ -39,11 +39,11 @@ namespace
     {
         SvStream& rStream;
         tsize_t nSize;
-        int nShortReads;
+        bool bAllowOneShortRead;
         Context(SvStream& rInStream, tsize_t nInSize)
             : rStream(rInStream)
             , nSize(nInSize)
-            , nShortReads(0)
+            , bAllowOneShortRead(false)
         {
         }
     };
@@ -55,10 +55,10 @@ static tsize_t tiff_read(thandle_t handle, tdata_t buf, tsize_t size)
     tsize_t nRead = pContext->rStream.ReadBytes(buf, size);
     // tdf#149417 allow one short read, which is similar to what
     // we do for jpeg since tdf#138950
-    if (nRead < size && !pContext->nShortReads)
+    if (nRead < size && pContext->bAllowOneShortRead)
     {
         memset(static_cast<char*>(buf) + nRead, 0, size - nRead);
-        ++pContext->nShortReads;
+        pContext->bAllowOneShortRead = false;
         return size;
     }
     return nRead;
@@ -190,6 +190,7 @@ bool ImportTiffGraphicImport(SvStream& rTIFF, Graphic& rGraphic)
             break;
 
         std::vector<uint32_t> raster(nPixelsRequired);
+        aContext.bAllowOneShortRead = true;
         if (TIFFReadRGBAImageOriented(tif, w, h, raster.data(), ORIENTATION_TOPLEFT, 1))
         {
             Bitmap bitmap(Size(w, h), vcl::PixelFormat::N24_BPP);