[Pcre-svn] [621] code/trunk/src/pcre2_fuzzsupport.c: Limit t…

Revision: 621

          http://www.exim.org/viewvc/pcre2?view=rev&revision=621
Author:   ph10
Date:     2016-12-20 17:10:30 +0000 (Tue, 20 Dec 2016)
Log Message:
-----------
Limit the fuzzing function with match limit = recursion limit = 100.

Modified Paths:
--------------
    code/trunk/src/pcre2_fuzzsupport.c

Modified: code/trunk/src/pcre2_fuzzsupport.c
===================================================================
--- code/trunk/src/pcre2_fuzzsupport.c    2016-12-20 16:47:41 UTC (rev 620)
+++ code/trunk/src/pcre2_fuzzsupport.c    2016-12-20 17:10:30 UTC (rev 621)
@@ -44,6 +44,7 @@
 uint32_t compile_options;
 uint32_t match_options;
 pcre2_match_data *match_data = NULL;
+pcre2_match_context *match_context = NULL;
 int r1, r2;
 int i;

@@ -120,7 +121,9 @@
     int j;
     uint32_t save_match_options = match_options;

-    /* Create a match data block only when we first need it. */
+    /* Create match data and context blocks only when we first need them. Set 
+    low match and recursion limits to avoid wasting too much searching large 
+    pattern trees. Almost all matches are going to fail. */

     if (match_data == NULL)
       {
@@ -134,6 +137,20 @@
         }
       }

+    if (match_context == NULL)
+      {
+      match_context = pcre2_match_context_create(NULL);
+      if (match_context == NULL)
+        {
+#ifdef STANDALONE
+        printf("** Failed to create match context block\n");
+#endif
+        return 0;
+        }
+      pcre2_set_match_limit(match_context, 100);
+      pcre2_set_recursion_limit(match_context, 100); 
+      }
+
     /* Match twice, with and without options */

     for (j = 0; j < 2; j++)
@@ -152,7 +169,7 @@
 #endif

       errorcode = pcre2_match(code, (PCRE2_SPTR)data, (PCRE2_SIZE)size, 0,
-        match_options, match_data, NULL);
+        match_options, match_data, match_context);

 #ifdef STANDALONE
       if (errorcode >= 0) printf("Match returned %d\n", errorcode); else
@@ -187,6 +204,8 @@
   }

if (match_data != NULL) pcre2_match_data_free(match_data);
+if (match_context != NULL) pcre2_match_context_free(match_context);
+
return 0;
}