Handle ConfigFileMode overflow and simplify regression test

Author: Diamagnetic

headers/modsecurity/rules_set_properties.h

@@ -267,6 +267,13 @@ class ConfigFileMode : public ConfigUnsignedInt {
             return false;
         }
 
+        if(val > std::numeric_limits<uint32_t>::max()) {
+            if(errmsg) {
+                *errmsg = "Value is too big.";
+            }
+            return false;
+        }
+
         m_value = static_cast<uint32_t>(val);
         m_set = true;
         return true;

test/test-cases/data/inspectFile-mode-600.lua

@@ -1,17 +1,11 @@
 #!/usr/bin/lua
 
 function main(filename)
-    local pipe = io.popen(string.format("stat -c %%a %q", filename), "r")
-    if pipe == nil then
+    local file = io.open(filename, "r")
+    if file == nil then
         return nil
     end
 
-    local mode = pipe:read("*l")
-    pipe:close()
-
-    if mode == "600" then
-        return "1"
-    end
-
-    return nil
+    file:close()
+    return "1"
 end