Re: [PATCH v5 net 1/6] net/sched: sch_ingress: Only create under TC_H_INGRESS

[Jamal Hadi Salim]

On Tue, May 23, 2023 at 9:18 PM Peilin Ye <yepeilin.cs@xxxxxxxxx> wrote:
>
> From: Peilin Ye <peilin.ye@xxxxxxxxxxxxx>
>
> ingress Qdiscs are only supposed to be created under TC_H_INGRESS.
> Return -EOPNOTSUPP if 'parent' is not TC_H_INGRESS, similar to
> mq_init().
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Reported-by: syzbot+b53a9c0d1ea4ad62da8b@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://lore.kernel.org/r/0000000000006cf87705f79acf1a@xxxxxxxxxx/
> Signed-off-by: Peilin Ye <peilin.ye@xxxxxxxxxxxxx>

Reviewed-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>

cheers,
jamal
> ---
> change in v5:
>   - avoid underflowing @ingress_needed_key in ->destroy(), reported by
>     Pedro
>
> change in v3, v4:
>   - add in-body From: tag
>
>  net/sched/sch_ingress.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
> index 84838128b9c5..f9ef6deb2770 100644
> --- a/net/sched/sch_ingress.c
> +++ b/net/sched/sch_ingress.c
> @@ -80,6 +80,9 @@ static int ingress_init(struct Qdisc *sch, struct nlattr *opt,
>         struct net_device *dev = qdisc_dev(sch);
>         int err;
>
> +       if (sch->parent != TC_H_INGRESS)
> +               return -EOPNOTSUPP;
> +
>         net_inc_ingress_queue();
>
>         mini_qdisc_pair_init(&q->miniqp, sch, &dev->miniq_ingress);
> @@ -101,6 +104,9 @@ static void ingress_destroy(struct Qdisc *sch)
>  {
>         struct ingress_sched_data *q = qdisc_priv(sch);
>
> +       if (sch->parent != TC_H_INGRESS)
> +               return;
> +
>         tcf_block_put_ext(q->block, sch, &q->block_info);
>         net_dec_ingress_queue();
>  }
> --
> 2.20.1
>