net/sched: act_ct: fix ref leak when switching zones

[ Upstream commit bcb74e132a ]

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 <fw@strlen.de>
Fixes: 2f131de361 ("net/sched: act_ct: Fix flow table lookup after ct clear or switching zones")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Marcelo Ricardo Leitner 2022-03-24 16:22:10 -03:00 committed by Greg Kroah-Hartman
parent 72dd9e61fa
commit bcbf4e5c3b

View file

@ -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,