[freetype2] master 235b1e2: [truetype]: Limit `SLOOP' bytecode argument to 16 bits.

[Werner LEMBERG]

branch: master
commit 235b1e2fe6ca325f449c5a73c75432d62d73f524
Author: Werner Lemberg <address@hidden>
Commit: Werner Lemberg <address@hidden>

    [truetype]: Limit `SLOOP' bytecode argument to 16 bits.
    
    This fixes
    
      https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7707
    
    * src/truetype/ttinterp.c (Ins_SLOOP): Do it.
---
 ChangeLog               | 10 ++++++++++
 src/truetype/ttinterp.c |  5 ++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index b929801..2f6bffc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2018-04-15  Werner Lemberg  <address@hidden>
+
+       [truetype]: Limit `SLOOP' bytecode argument to 16 bits.
+
+       This fixes
+
+         https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7707
+
+       * src/truetype/ttinterp.c (Ins_SLOOP): Do it.
+
 2018-04-14  Werner Lemberg  <address@hidden>
 
        [truetype] Integer overflow issues.
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index d9865d4..c66c699 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -3289,7 +3289,10 @@
     if ( args[0] < 0 )
       exc->error = FT_THROW( Bad_Argument );
     else
-      exc->GS.loop = args[0];
+    {
+      /* we heuristically limit the number of loops to 16 bits */
+      exc->GS.loop = args[0] > 0xFFFFL ? 0xFFFFL : args[0];
+    }
   }