lazy image loading shouldn't read the entire .xls file (tdf#124828)

b11188835d3b87cd changed msfilter to use
GraphicFilter::ImportUnloadedGraphic() to lazy-load images
from the document. However, that function in some cases simply
reads the entire rest of the passed SvStream, which in this case
is the entire .xls file. And the document from tdf#124828 is ~50MiB
and contains ~4000 images => 100+ GiB memory required.

Change-Id: I74926383204ec642eabb28b62e2cf2e1ff8054a9
Reviewed-on: https://gerrit.libreoffice.org/71136
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
(cherry picked from commit af84fc9d906626255aaf136eefc5e55236e0e8a6)
Reviewed-on: https://gerrit.libreoffice.org/71221
Reviewed-by: Xisco Faulí <xiscofauli@libreoffice.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/filter/source/msfilter/msdffimp.cxx b/filter/source/msfilter/msdffimp.cxx
index 30dc80c92f8b..c9087180ecdf 100644
--- a/filter/source/msfilter/msdffimp.cxx
+++ b/filter/source/msfilter/msdffimp.cxx
@@ -6553,7 +6553,11 @@ bool SvxMSDffManager::GetBLIPDirect( SvStream& rBLIPStream, Graphic& rData, tool
         else
         {   // and unleash our filter
             GraphicFilter& rGF = GraphicFilter::GetGraphicFilter();
-            Graphic aGraphic = rGF.ImportUnloadedGraphic(*pGrStream);
+            // ImportUnloadedGraphic() may simply read the entire rest of the stream,
+            // which may be very large if the whole document is large. Limit the read
+            // size to the size of this record.
+            sal_uInt64 maxSize = pGrStream == &rBLIPStream ? nLength : 0;
+            Graphic aGraphic = rGF.ImportUnloadedGraphic(*pGrStream, maxSize);
             if (aGraphic)
             {
                 rData = aGraphic;