diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 1bbe3a990ef1cbb7d88caee48673c4c4a66b7fc0..655f79db7899ffd0628714d51203847630a8075c 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/initrd.h>
 #include <linux/memblock.h>
+#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/of_reserved_mem.h>
@@ -436,6 +437,8 @@ static void *kernel_tree_alloc(u64 size, u64 align)
 	return kzalloc(size, GFP_KERNEL);
 }
 
+static DEFINE_MUTEX(of_fdt_unflatten_mutex);
+
 /**
  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
  *
@@ -447,7 +450,9 @@ static void *kernel_tree_alloc(u64 size, u64 align)
 void of_fdt_unflatten_tree(const unsigned long *blob,
 			struct device_node **mynodes)
 {
+	mutex_lock(&of_fdt_unflatten_mutex);
 	__unflatten_device_tree(blob, mynodes, &kernel_tree_alloc);
+	mutex_unlock(&of_fdt_unflatten_mutex);
 }
 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);