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Message-ID: <803f6502-76dc-d6e6-1bb2-5632de12e5ee@mojatatu.com>
Date:   Thu, 20 Apr 2023 15:41:17 -0300
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Subject: Re: [PATCH net v2] net/sched: cls_api: Initialize miss_cookie_node
 when action miss is not used
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To:     Ivan Vecera <ivecera@redhat.com>, netdev@vger.kernel.org
Cc:     Jamal Hadi Salim <jhs@mojatatu.com>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Simon Horman <simon.horman@corigine.com>,
        Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
        open list <linux-kernel@vger.kernel.org>
References: <20230420183634.1139391-1-ivecera@redhat.com>
From:   Pedro Tammela <pctammela@mojatatu.com>
In-Reply-To: <20230420183634.1139391-1-ivecera@redhat.com>
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On 20/04/2023 15:36, Ivan Vecera wrote:
> Function tcf_exts_init_ex() sets exts->miss_cookie_node ptr only
> when use_action_miss is true so it assumes in other case that
> the field is set to NULL by the caller. If not then the field
> contains garbage and subsequent tcf_exts_destroy() call results
> in a crash.
> Ensure that the field .miss_cookie_node pointer is NULL when
> use_action_miss parameter is false to avoid this potential scenario.
> 
> Fixes: 80cd22c35c90 ("net/sched: cls_api: Support hardware miss to tc action")
> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
> ---
>   net/sched/cls_api.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
> index 35785a36c80298..3c3629c9e7b65c 100644
> --- a/net/sched/cls_api.c
> +++ b/net/sched/cls_api.c
> @@ -3211,6 +3211,7 @@ int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action,
>   #ifdef CONFIG_NET_CLS_ACT
>   	exts->type = 0;
>   	exts->nr_actions = 0;
> +	exts->miss_cookie_node = NULL;
>   	/* Note: we do not own yet a reference on net.
>   	 * This reference might be taken later from tcf_exts_get_net().
>   	 */

Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>