ofz#4539 depth protect mathtype parser

Change-Id: I46e12f52d56e7802b676309207904b4d1894d236
Reviewed-on: https://gerrit.libreoffice.org/45928
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/starmath/inc/parse.hxx b/starmath/inc/parse.hxx
index 1bcef035d5b2..5d1eeef553d4 100644
--- a/starmath/inc/parse.hxx
+++ b/starmath/inc/parse.hxx
@@ -41,6 +41,24 @@ class SmParser
                     m_nColOff; // 0-based
     bool            m_bImportSymNames,
                     m_bExportSymNames;
+    sal_Int32       m_nParseDepth;
+
+    class DepthProtect
+    {
+    private:
+        sal_Int32& m_rParseDepth;
+    public:
+        DepthProtect(sal_Int32& rParseDepth)
+            : m_rParseDepth(rParseDepth)
+        {
+            ++m_rParseDepth;
+        }
+        bool TooDeep() const { return m_rParseDepth > 2048; }
+        ~DepthProtect()
+        {
+            --m_rParseDepth;
+        }
+    };
 
     // map of used symbols (used to reduce file size by exporting only actually used symbols)
     std::set< OUString >   m_aUsedSymbols;