diff --git a/drivers/video/fbdev/msm/mdss_dsi.c b/drivers/video/fbdev/msm/mdss_dsi.c
index 7b6153503af5..0d41f41371dd 100644
--- a/drivers/video/fbdev/msm/mdss_dsi.c
+++ b/drivers/video/fbdev/msm/mdss_dsi.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -760,7 +760,7 @@ static ssize_t mdss_dsi_cmd_state_read(struct file *file, char __user *buf,
 	if (blen < 0)
 		return 0;
 
-	if (copy_to_user(buf, buffer, blen))
+	if (copy_to_user(buf, buffer, min(count, (size_t)blen+1)))
 		return -EFAULT;
 
 	*ppos += blen;