Re: [PATCH net v2] net/sched: cls_api: Initialize miss_cookie_node when action miss is not used

[Pedro Tammela]

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@xxxxxxxxxx>
> ---
>   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@xxxxxxxxxxxx>