diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index ff64bcd..6314629 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -473,6 +473,7 @@
 	if (copy_from_user(buf, user_buf, buf_size))
 		return -EFAULT;
 
+	buf[buf_size] = '\0';
 	if (strtobool(buf, &bv) == 0)
 		*val = bv;