gfxmenu/gui: Check printf() format in the gui_progress_bar and gui_label

The gui_progress_bar and gui_label components can display the timeout
value. The format string can be set through a theme file. This patch
adds a validation step to the format string.

If a user loads a theme file into the GRUB without this patch then
a GUI label with the following settings

  + label {
  ...
  id = "__timeout__"
  text = "%s"
  }

will interpret the current timeout value as string pointer and print the
memory at that position on the screen. It is not desired behavior.

Signed-off-by: Thomas Frauendorfer | Miray Software <tf@miray.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Thomas Frauendorfer | Miray Software 2020-08-04 13:49:51 +02:00 committed by Daniel Kiper
parent 83603bea6c
commit 42facd5772
2 changed files with 7 additions and 0 deletions

View File

@ -193,6 +193,10 @@ label_set_property (void *vself, const char *name, const char *value)
else if (grub_strcmp (value, "@KEYMAP_SHORT@") == 0)
value = _("enter: boot, `e': options, `c': cmd-line");
/* FIXME: Add more templates here if needed. */
if (grub_printf_fmt_check(value, "%d") != GRUB_ERR_NONE)
value = ""; /* Unsupported format. */
self->template = grub_strdup (value);
self->text = grub_xasprintf (value, self->value);
}

View File

@ -348,6 +348,9 @@ progress_bar_set_property (void *vself, const char *name, const char *value)
Please use the shortest form available in you language. */
value = _("%ds");
if (grub_printf_fmt_check(value, "%d") != GRUB_ERR_NONE)
value = ""; /* Unsupported format. */
self->template = grub_strdup (value);
}
else if (grub_strcmp (name, "font") == 0)