Re: [PATCH] Btrfs: fix use-after-free when cloning a trailing file hole

[Chris Mason <clm@fb.com>]

On 06/29/2014 03:43 PM, Filipe David Borba Manana wrote:
> The transaction handle was being used after being freed.
> 
> Cc: Chris Mason <clm@fb.com>
> Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
> ---
>  fs/btrfs/ioctl.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 02dc64b..2562dc7 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3565,12 +3565,10 @@ process_slot:
>  			btrfs_end_transaction(trans, root);
>  			goto out;
>  		}
> -		ret = clone_finish_inode_update(trans, inode, destoff + len,
> -						destoff, olen);
> -		if (ret)
> -			goto out;
>  		clone_update_extent_map(inode, trans, path, NULL, last_dest_end,
>  					destoff + len - last_dest_end);
> +		ret = clone_finish_inode_update(trans, inode, destoff + len,
> +						destoff, olen);
>  	}
>  
>  out:
> 

What about the path?  It has been released, so it should either be NULL
or we have other problems ;)

-chris