net/sched: act_ct: Fix ct template allocation for zone 0

[ Upstream commit fb91702b743dec78d6507c53a2dec8a8883f509d ]

Fix current behavior of skipping template allocation in case the
ct action is in zone 0.

Skipping the allocation may cause the datapath ct code to ignore the
entire ct action with all its attributes (commit, nat) in case the ct
action in zone 0 was preceded by a ct clear action.

The ct clear action sets the ct_state to untracked and resets the
skb->_nfct pointer. Under these conditions and without an allocated
ct template, the skb->_nfct pointer will remain NULL which will
cause the tc ct action handler to exit without handling commit and nat
actions, if such exist.

For example, the following rule in OVS dp:
recirc_id(0x2),ct_state(+new-est-rel-rpl+trk),ct_label(0/0x1), \
in_port(eth0),actions:ct_clear,ct(commit,nat(src=10.11.0.12)), \
recirc(0x37a)

Will result in act_ct skipping the commit and nat actions in zone 0.

The change removes the skipping of template allocation for zone 0 and
treats it the same as any other zone.

Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: Ariel Levkovich <lariel@nvidia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Link: https://lore.kernel.org/r/20210526170110.54864-1-lariel@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 6376b7b223256453d1a731ca1b1efed3125f3549..315a5b2f3add84145820e1a4475911af2a80cfab 100644 (file)
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -1199,9 +1199,6 @@ static int tcf_ct_fill_params(struct net *net,
                                   sizeof(p->zone));
        }
 
-       if (p->zone == NF_CT_DEFAULT_ZONE_ID)
-               return 0;
-
        nf_ct_zone_init(&zone, p->zone, NF_CT_DEFAULT_ZONE_DIR, 0);
        tmpl = nf_ct_tmpl_alloc(net, &zone, GFP_KERNEL);
        if (!tmpl) {