diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2ebcb33966bb..2606b3029e1b 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4603,7 +4603,7 @@ static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
 		return -ENOMEM;
 
 	space_args.total_spaces = 0;
-	dest = kmalloc(alloc_size, GFP_KERNEL);
+	dest = kzalloc(alloc_size, GFP_KERNEL);
 	if (!dest)
 		return -ENOMEM;
 	dest_orig = dest;
@@ -4662,7 +4662,8 @@ static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
 	user_dest = (struct btrfs_ioctl_space_info __user *)
 		(arg + sizeof(struct btrfs_ioctl_space_args));
 
-	if (copy_to_user(user_dest, dest_orig, alloc_size))
+	if (copy_to_user(user_dest, dest_orig,
+		 space_args.total_spaces * sizeof(*dest_orig)))
 		ret = -EFAULT;
 
 	kfree(dest_orig);