Re: [SPAM] [PATCH] 9pfs: simplify v9fs_walk()

[Greg Kurz]

On Sun, 16 May 2021 17:55:34 +0200
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:

> There is only one comparison between nwnames and P9_MAXWELEM required.
> 
> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> ---

Nice catch. It's been there for a decade :)

Reviewed-by: Greg Kurz <groug@kaod.org>

>  hw/9pfs/9p.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> index 0fa776af09..89aa07db78 100644
> --- a/hw/9pfs/9p.c
> +++ b/hw/9pfs/9p.c
> @@ -1739,7 +1739,11 @@ static void coroutine_fn v9fs_walk(void *opaque)
>  
>      trace_v9fs_walk(pdu->tag, pdu->id, fid, newfid, nwnames);
>  
> -    if (nwnames && nwnames <= P9_MAXWELEM) {
> +    if (nwnames > P9_MAXWELEM) {
> +        err = -EINVAL;
> +        goto out_nofid;
> +    }
> +    if (nwnames) {
>          wnames = g_new0(V9fsString, nwnames);
>          qids   = g_new0(V9fsQID, nwnames);
>          for (i = 0; i < nwnames; i++) {
> @@ -1753,9 +1757,6 @@ static void coroutine_fn v9fs_walk(void *opaque)
>              }
>              offset += err;
>          }
> -    } else if (nwnames > P9_MAXWELEM) {
> -        err = -EINVAL;
> -        goto out_nofid;
>      }
>      fidp = get_fid(pdu, fid);
>      if (fidp == NULL) {