From: Ivan Vecera <ivecera@xxxxxxxxxx> [ Upstream commit 2cc8a008d62f3c04eeb7ec6fe59e542802bb8df3 ] 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> Reviewed-by: Pedro Tammela <pctammela@xxxxxxxxxxxx> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230420183634.1139391-1-ivecera@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@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 35785a36c8029..3c3629c9e7b65 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(). */ -- 2.39.2