diff --git a/drivers/staging/lustre/lustre/include/lustre_net.h b/drivers/staging/lustre/lustre/include/lustre_net.h
index 745adbb74cfce7eb34a8ba11cd5ce9a8c7ee23ee..7640e179e39db47ca00120b9d75b19fafeddae56 100644
--- a/drivers/staging/lustre/lustre/include/lustre_net.h
+++ b/drivers/staging/lustre/lustre/include/lustre_net.h
@@ -264,6 +264,8 @@
 #define LDLM_MAXREQSIZE   (5 * 1024)
 #define LDLM_MAXREPSIZE   (1024)
 
+#define MDS_MAXREQSIZE		(5 * 1024)	/* >= 4736 */
+
 #define OST_MAXREQSIZE		(5 * 1024)
 
 /* Macro to hide a typecast. */
diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index 7fbc18e3e654a19484b8f7c028f9964256eea72c..c391b60394e4183760d77c184fdb5035cc37adbf 100644
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -1804,6 +1804,11 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		/* Compute the whole struct size */
 		totalsize = hur_len(hur);
 		OBD_FREE_PTR(hur);
+
+		/* Final size will be more than double totalsize */
+		if (totalsize >= MDS_MAXREQSIZE / 3)
+			return -E2BIG;
+
 		OBD_ALLOC_LARGE(hur, totalsize);
 		if (hur == NULL)
 			return -ENOMEM;