From bcbf4e5c3b5b373cd61528392dd1ec8e9c0fd33d Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 24 Mar 2022 16:22:10 -0300 Subject: [PATCH] net/sched: act_ct: fix ref leak when switching zones [ Upstream commit bcb74e132a76ce0502bb33d5b65533a4ed72d159 ] When switching zones or network namespaces without doing a ct clear in between, it is now leaking a reference to the old ct entry. That's because tcf_ct_skb_nfct_cached() returns false and tcf_ct_flow_table_lookup() may simply overwrite it. The fix is to, as the ct entry is not reusable, free it already at tcf_ct_skb_nfct_cached(). Reported-by: Florian Westphal Fixes: 2f131de361f6 ("net/sched: act_ct: Fix flow table lookup after ct clear or switching zones") Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/sched/act_ct.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c index 240b3c5d2eb1..553bf41671a6 100644 --- a/net/sched/act_ct.c +++ b/net/sched/act_ct.c @@ -583,22 +583,25 @@ static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb, if (!ct) return false; if (!net_eq(net, read_pnet(&ct->ct_net))) - return false; + goto drop_ct; if (nf_ct_zone(ct)->id != zone_id) - return false; + goto drop_ct; /* Force conntrack entry direction. */ if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) { if (nf_ct_is_confirmed(ct)) nf_ct_kill(ct); - nf_ct_put(ct); - nf_ct_set(skb, NULL, IP_CT_UNTRACKED); - - return false; + goto drop_ct; } return true; + +drop_ct: + nf_ct_put(ct); + nf_ct_set(skb, NULL, IP_CT_UNTRACKED); + + return false; } /* Trim the skb to the length specified by the IP/IPv6 header,