Re: [PATCH for-next 6/7] RDMA/rtrs: Do not allow sessname to contain special symbols / and .

[Leon Romanovsky <leon@kernel.org>]

On Wed, Sep 22, 2021 at 02:53:32PM +0200, Md Haris Iqbal wrote:
> Allowing these characters in sessname can lead to unexpected results,
> particularly because / is used as a separator between files in a path,
> and . points to the current directory.
> 
> Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
> Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
> Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
> ---
>  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 6 ++++++
>  drivers/infiniband/ulp/rtrs/rtrs-srv.c | 5 +++++
>  2 files changed, 11 insertions(+)

It will be safer if you check for only allowed symbols and disallow
everything else. Check for: a-Z, 0-9 and "-".

Thanks

> 
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> index bc8824b4ee0d..15c0077dd27e 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> @@ -2788,6 +2788,12 @@ struct rtrs_clt *rtrs_clt_open(struct rtrs_clt_ops *ops,
>  	struct rtrs_clt *clt;
>  	int err, i;
>  
> +	if (strchr(sessname, '/') || strchr(sessname, '.')) {
> +		pr_err("sessname cannot contain / and .\n");
> +		err = -EINVAL;
> +		goto out;
> +	}
> +
>  	clt = alloc_clt(sessname, paths_num, port, pdu_sz, ops->priv,
>  			ops->link_ev,
>  			reconnect_delay_sec,
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> index 078a1cbac90c..7df71f8cf149 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> @@ -803,6 +803,11 @@ static int process_info_req(struct rtrs_srv_con *con,
>  		return err;
>  	}
>  
> +	if (strchr(msg->sessname, '/') || strchr(msg->sessname, '.')) {
> +		rtrs_err(s, "sessname cannot contain / and .\n");
> +		return -EINVAL;
> +	}
> +
>  	if (exist_sessname(sess->srv->ctx,
>  			   msg->sessname, &sess->srv->paths_uuid)) {
>  		rtrs_err(s, "sessname is duplicated: %s\n", msg->sessname);
> -- 
> 2.25.1
>