On Tue, Sep 28, 2021 at 09:08:26AM +0200, Jack Wang wrote:
> Leon Romanovsky <leon@xxxxxxxxxx> 于2021年9月27日周一 下午2:23写道：
> >
> > 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@xxxxxxxxx>
> > > Reviewed-by: Gioh Kim <gi-oh.kim@xxxxxxxxx>
> > > Reviewed-by: Aleksei Marov <aleksei.marov@xxxxxxxxx>
> > > ---
> > > 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 "-".
> >
> Hi Leon,
>
> Thanks for your suggestions.
> The reasons we choose to do disallow only '/' and '.':
> 1 more flexible, most UNIX filenames allow any 8-bit set, except '/' and null.
So you need to add all possible protections and checks that VFS has to allow "random" name.
> 2 matching for 2 characters is faster than checking all the allowed
> symbols during session establishment.
Extra CPU cycles won't make any difference here.
> 3 we do use hostnameA@hostnameB for production usage right now, we
> don't want to break the user space.
You can add "@" into the list of accepted symbols.
>
> I hope this makes sense to you.
>
> Regards!
>
> >
> > >
> > > 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
> > >
