Re: [PATCH] net: sched: hfsc: dont intepret cls results when asked to drop

From: Eric Dumazet
Date: Fri Sep 15 2023 - 08:57:51 EST


On Fri, Sep 15, 2023 at 2:37 PM Ma Ke <make_ruc2021@xxxxxxx> wrote:
>
> If asked to drop a packet via TC_ACT_SHOT it is unsafe to assume
> res.class contains a valid pointer.
>
> Signed-off-by: Ma Ke <make_ruc2021@xxxxxxx>
> ---
> net/sched/sch_hfsc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
> index 3554085bc2be..2a76027b14e6 100644
> --- a/net/sched/sch_hfsc.c
> +++ b/net/sched/sch_hfsc.c
> @@ -1135,6 +1135,8 @@ hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
> head = &q->root;
> tcf = rcu_dereference_bh(q->root.filter_list);
> while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
> + if (result == TC_ACT_SHOT)
> + return NULL;
> #ifdef CONFIG_NET_CLS_ACT
> switch (result) {
> case TC_ACT_QUEUED:
> --
> 2.37.2
>

Same comment, already handled at iine 1145