Re: [PATCH] xfs: fix return of uninitialized value in variable error

[Brian Foster]

On Fri, Apr 09, 2021 at 03:18:34PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> A previous commit removed a call to xfs_attr3_leaf_read that
> assigned an error return code to variable error. We now have
> a few early error return paths to label 'out' that return
> error if error is set; however error now is uninitialized
> so potentially garbage is being returned.  Fix this by setting
> error to zero to restore the original behaviour where error
> was zero at the label 'restart'.
> 
> Addresses-Coverity: ("Uninitialized scalar variable")
> Fixes: 07120f1abdff ("xfs: Add xfs_has_attr and subroutines")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
>  fs/xfs/libxfs/xfs_attr.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index 472b3039eabb..902e5f7e6642 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
> @@ -928,6 +928,7 @@ xfs_attr_node_addname(
>  	 * Search to see if name already exists, and get back a pointer
>  	 * to where it should go.
>  	 */
> +	error = 0;
>  	retval = xfs_attr_node_hasname(args, &state);
>  	if (retval != -ENOATTR && retval != -EEXIST)
>  		goto out;

I think it would be nicer to initialize at the top of the function as
opposed to try and "preserve" historical behavior, but that nit aside:

Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>

> -- 
> 2.30.2
>