consume AFL++ status value in SHM input fuzzing mode

Author: Scepticz

harness/fuzzware_harness/native/native_hooks.c

@@ -116,6 +116,7 @@ uint8_t coverage_bitmap[MAP_SIZE];
 static void determine_input_mode() {
     char *id_str;
     int shm_id;
+    int tmp;
 
     id_str = getenv(SHM_FUZZ_ENV_VAR);
     if (id_str) {
@@ -125,6 +126,13 @@ static void determine_input_mode() {
             perror("[!] could not access fuzzing shared memory");
             exit(1);
         }
+
+        // AFL++ detected. Read its status value
+        if(read(FORKSRV_FD, &tmp, 4) != 4) {
+            perror("[!] did not receive AFL++ status value");
+            exit(1);
+        }
+
         input_mode_SHM = true;
     }
 }