Security: Add extra check range checks in Featureless Make build skeleton.

The used - 1 could be a problem if used is 0.

diff --git a/level_3/fake/c/private-build-skeleton.c b/level_3/fake/c/private-build-skeleton.c
index e3b60ca9ac01929b49de77c215d71cb6efdd5d28..8e15020207aa40a9a8b26a797a9f531d864f1db1 100644 (file)
--- a/level_3/fake/c/private-build-skeleton.c
+++ b/level_3/fake/c/private-build-skeleton.c
@@ -56,6 +56,7 @@ extern "C" {
     }
 
     bool created = F_false;
+    f_array_length_t j = 0;
 
     for (uint8_t i = 0; i < 19; ++i) {
 
@@ -63,9 +64,9 @@ extern "C" {
 
       created = F_false;
 
-      for (f_array_length_t j = 0; j < directorys[i]->used; ++j) {
+      for (j = 0; j < directorys[i]->used; ++j) {
 
-        if (directorys[i]->string[j] != f_path_separator_s.string[0]) continue;
+        if (f_path_separator_s.used && directorys[i]->string[j] != f_path_separator_s.string[0]) continue;
 
         directorys[i]->string[j] = 0;
 
@@ -88,7 +89,7 @@ extern "C" {
         if (F_status_is_error(*status)) break;
       } // for
 
-      if (F_status_is_fine(*status) && directorys[i]->string[directorys[i]->used - 1] != f_path_separator_s.string[0]) {
+      if (F_status_is_fine(*status) && directorys[i]->used && f_path_separator_s.used && directorys[i]->string[directorys[i]->used - 1] != f_path_separator_s.string[0]) {
         *status = f_directory_exists(*directorys[i]);
 
         if (F_status_is_error_not(*status)) {