Patch-Magento_Configurable_M2.1.x-fix-get-price.patch

--- Model/Product/Type/Configurable/Price.php
+++ Model/Product/Type/Configurable/Price.php
@@ -39,10 +39,15 @@
      */
     public function getPrice($product)
     {
-        if ($product->getCustomOption('simple_product')) {
-            return $product->getCustomOption('simple_product')->getProduct()->getPrice();
-        } else {
-            return 0;
+        if (!empty($product)) {
+            $simpleProductOption = $product->getCustomOption('simple_product');
+            if (!empty($simpleProductOption)) {
+                $simpleProduct = $simpleProductOption->getProduct();
+                if (!empty($simpleProduct)) {
+                    return $simpleProduct->getPrice();
+                }
+            }
         }
+        return 0;
     }
 }