net/sched: act_ct: Fix flow table lookup after ct clear or switching zones

BugLink: https://bugs.launchpad.net/bugs/1963891
commit 2f131de361f6d0eaff17db26efdb844c178432f8 upstream.

Flow table lookup is skipped if packet either went through ct clear
action (which set the IP_CT_UNTRACKED flag on the packet), or while
switching zones and there is already a connection associated with
the packet. This will result in no SW offload of the connection,
and the and connection not being removed from flow table with
TCP teardown (fin/rst packet).

To fix the above, remove these unneccary checks in flow
table lookup.

Fixes: 46475bb20f4b ("net/sched: act_ct: Software offload of established flows")
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 2a17eb77c9049fd67571bc92911e43ab2d1d8360..4ffea1290ce1c928cbcae86480753a5fded865f1 100644 (file)
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -516,11 +516,6 @@ static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
        struct nf_conn *ct;
        u8 dir;
 
-       /* Previously seen or loopback */
-       ct = nf_ct_get(skb, &ctinfo);
-       if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
-               return false;
-
        switch (family) {
        case NFPROTO_IPV4:
                if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple, &tcph))