hs-v3: Don't BUG() on directory permission check failure

In hs_config.c, we do validate the permission of the hidden service directory
but we do not try to create it. So, in the event that the directory doesn't
exists, we end up in the loading key code path which checks for the
permission and possibly creates the directory. On failure, don't BUG() since
there is a perfectly valid use case for that function to fail.

Fixes #27335

Signed-off-by: David Goulet <dgoulet@torproject.org>

changes/bug27335

@@ -0,0 +1,4 @@
+  o Minor bugfixes (hidden service v3):
+    - In case the hidden service directory can't be created or has wrong
+      permissions, do not BUG() on it which lead to a non fatal stacktrace.
+      Fixes bug 27335; bugfix on 0.3.2.1.

src/or/hs_service.c

@@ -974,9 +974,9 @@ load_service_keys(hs_service_t *service)
    * files to that directory so make sure it exists and has the right
    * permissions. We do this here because at this stage we know that Tor is
    * actually running and the service we have has been validated. */
-  if (BUG(hs_check_service_private_dir(get_options()->User,
-                                       config->directory_path,
-                                       config->dir_group_readable, 1) < 0)) {
+  if (hs_check_service_private_dir(get_options()->User,
+                                   config->directory_path,
+                                   config->dir_group_readable, 1) < 0) {
     goto end;
   }