diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c index c6d6a6fe9602..a59a8ad38721 100644 --- a/net/sched/act_ct.c +++ b/net/sched/act_ct.c @@ -1038,6 +1038,14 @@ do_nat: */ if (nf_conntrack_confirm(skb) != NF_ACCEPT) goto drop; + + /* The ct may be dropped if a clash has been resolved, + * so it's necessary to retrieve it from skb again to + * prevent UAF. + */ + ct = nf_ct_get(skb, &ctinfo); + if (!ct) + skip_add = true; } if (!skip_add)