Fix double free after b19bfa1e207a8d4972bfc701fde5d5c014f95383

4 files changed, 10 insertions, 6 deletions

diff --git a/src/lib/third_party/include/actypes.h b/src/lib/third_party/include/actypes.h
index 5a94b63a1..2308cd686 100644
--- a/src/lib/third_party/include/actypes.h
+++ b/src/lib/third_party/include/actypes.h
@@ -63,6 +63,7 @@ typedef struct
 {
   AC_ALPHABET_t * astring; /* String of alphabets */
   unsigned int length; /* Length of pattern */
+  u_int8_t is_existing; /* 1 if the node is already part of another AC_PATTERN_t */
   AC_REP_t rep; /* Representative string (optional) */
 } AC_PATTERN_t;
 
diff --git a/src/lib/third_party/include/node.h b/src/lib/third_party/include/node.h
index 30836df6a..c172112aa 100644
--- a/src/lib/third_party/include/node.h
+++ b/src/lib/third_party/include/node.h
@@ -55,7 +55,7 @@ struct edge
 
 AC_NODE_t * node_create            (void);
 AC_NODE_t * node_create_next       (AC_NODE_t * thiz, AC_ALPHABET_t alpha);
-void        node_register_matchstr (AC_NODE_t * thiz, AC_PATTERN_t * str);
+void        node_register_matchstr (AC_NODE_t * thiz, AC_PATTERN_t * str, u_int8_t is_existing);
 void        node_register_outgoing (AC_NODE_t * thiz, AC_NODE_t * next, AC_ALPHABET_t alpha);
 AC_NODE_t * node_find_next         (AC_NODE_t * thiz, AC_ALPHABET_t alpha);
 AC_NODE_t * node_findbs_next       (AC_NODE_t * thiz, AC_ALPHABET_t alpha);
diff --git a/src/lib/third_party/src/ahocorasick.c b/src/lib/third_party/src/ahocorasick.c
index db398cfcd..ffa8bac77 100644
--- a/src/lib/third_party/src/ahocorasick.c
+++ b/src/lib/third_party/src/ahocorasick.c
@@ -108,7 +108,7 @@ AC_ERROR_t ac_automata_add (AC_AUTOMATA_t * thiz, AC_PATTERN_t * patt)
     return ACERR_DUPLICATE_PATTERN;
 
   n->final = 1;
-  node_register_matchstr(n, patt);
+  node_register_matchstr(n, patt, 0);
   thiz->total_patterns++;
 
   return ACERR_SUCCESS;
@@ -327,7 +327,7 @@ static void ac_automata_union_matchstrs (AC_NODE_t * node)
   while ((m = m->failure_node))
     {
       for (i=0; i < m->matched_patterns_num; i++)
-	node_register_matchstr(node, &(m->matched_patterns[i]));
+	node_register_matchstr(node, &(m->matched_patterns[i]), 1 /* this is an existing node */);
 
       if (m->final)
 	node->final = 1;
diff --git a/src/lib/third_party/src/node.c b/src/lib/third_party/src/node.c
index 3eda50461..96e25e8af 100644
--- a/src/lib/third_party/src/node.c
+++ b/src/lib/third_party/src/node.c
@@ -76,8 +76,10 @@ void node_init(AC_NODE_t * thiz)
 void node_release(AC_NODE_t * thiz, u_int8_t free_pattern)
 {
   if(free_pattern) {
-    for(int i=0; i<thiz->matched_patterns_num; i++)
-      ndpi_free(thiz->matched_patterns[i].astring);
+    for(int i=0; i<thiz->matched_patterns_num; i++) {
+      if(!thiz->matched_patterns[i].is_existing)
+        ndpi_free(thiz->matched_patterns[i].astring);
+    }
   }
 
   ndpi_free(thiz->matched_patterns);
@@ -179,7 +181,7 @@ AC_NODE_t * node_create_next (AC_NODE_t * thiz, AC_ALPHABET_t alpha)
  * FUNCTION: node_register_matchstr
  * Adds the pattern to the list of accepted pattern.
  ******************************************************************************/
-void node_register_matchstr (AC_NODE_t * thiz, AC_PATTERN_t * str)
+void node_register_matchstr (AC_NODE_t * thiz, AC_PATTERN_t * str, u_int8_t is_existing)
 {
   /* Check if the new pattern already exists in the node list */
   if (node_has_matchstr(thiz, str))
@@ -197,6 +199,7 @@ void node_register_matchstr (AC_NODE_t * thiz, AC_PATTERN_t * str)
 
   thiz->matched_patterns[thiz->matched_patterns_num].astring = str->astring;
   thiz->matched_patterns[thiz->matched_patterns_num].length = str->length;
+  thiz->matched_patterns[thiz->matched_patterns_num].is_existing = is_existing;
   memcpy(&thiz->matched_patterns[thiz->matched_patterns_num].rep, &str->rep, sizeof(AC_REP_t));
   thiz->matched_patterns_num++;
 }