:)

.gitlab-ci.yml

+image: archlinux:latest
+
+fuzzertest: 
+  script: 
+    - pacman -Syu --noconfirm make clang cmake
+    - mkdir build
+    - cd build
+    - CC=clang cmake ..
+    - make
+    - ./tests/utility_fuzzer_test -max_total_time=60

main.c

@@ -4,9 +4,10 @@
 #include <stdlib.h>
 
 int main() {
-  char test[] = "hei&der<borte>!";
+  const char *test = "hei&der<borte>!";
   size_t size = strlen(test);
-  printf("%s\n", combineStrings(test, size));
+  const char *res = combineStrings(test, size);
+  printf("%s\n", res);
+  free(res);
   return 0;
 }
\ No newline at end of file
-

tests/utility_fuzzer_test.c

@@ -3,7 +3,6 @@
 #include <stdint.h>
 
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  combineStrings((const char *)data, size);
+  free(combineStrings((const char *)data, size));
   return 0;
 }
\ No newline at end of file
-

utility.h

@@ -2,33 +2,38 @@
 #include <stdbool.h>
 #include <stddef.h>
 
-const char* combineStrings(char *msg, size_t size){
+const char* combineStrings(const char *msg, size_t size){
     int i;
     char* temp;
+    size_t counter = 1;
     temp = malloc(size*5+1);
+    temp[0] = '\0'; 
 
     for (i = 0; i < size; ++i)
     {
         if(msg[i] == '&')
         {
             strcat(temp, "&amp;");
+            counter += 5;
         }
         else if(msg[i] == '>')
         {
             strcat(temp,"&gt;");
+            counter += 4;
         }
         else if(msg[i] == '<')
         {
             strcat(temp,"&lt;");
+            counter += 4;
         }
         else
         {
             strncat(temp,&msg[i],1);
+            counter += 1; 
         }
 
     }
-    return temp;
 
+    temp = realloc(temp, counter);
+    return temp;
 }
\ No newline at end of file
-
-