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authorIlya Maximets <i.maximets@ovn.org>2022-06-07 00:11:40 +0200
committerJakub Kicinski <kuba@kernel.org>2022-06-08 20:49:52 -0700
commit2061ecfdf2350994e5b61c43e50e98a7a70e95ee (patch)
tree699876e3ea74a0ff98170aa28a70e65aef76af1d /net
parent2f2c0d2919a14002760f89f4e02960c735a316d2 (diff)
net: openvswitch: fix misuse of the cached connection on tuple changes
If packet headers changed, the cached nfct is no longer relevant for the packet and attempt to re-use it leads to the incorrect packet classification. This issue is causing broken connectivity in OpenStack deployments with OVS/OVN due to hairpin traffic being unexpectedly dropped. The setup has datapath flows with several conntrack actions and tuple changes between them: actions:ct(commit,zone=8,mark=0/0x1,nat(src)), set(eth(src=00:00:00:00:00:01,dst=00:00:00:00:00:06)), set(ipv4(src=172.18.2.10,dst=192.168.100.6,ttl=62)), ct(zone=8),recirc(0x4) After the first ct() action the packet headers are almost fully re-written. The next ct() tries to re-use the existing nfct entry and marks the packet as invalid, so it gets dropped later in the pipeline. Clearing the cached conntrack entry whenever packet tuple is changed to avoid the issue. The flow key should not be cleared though, because we should still be able to match on the ct_state if the recirculation happens after the tuple change but before the next ct() action. Cc: stable@vger.kernel.org Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action") Reported-by: Frode Nordahl <frode.nordahl@canonical.com> Link: https://mail.openvswitch.org/pipermail/ovs-discuss/2022-May/051829.html Link: https://bugs.launchpad.net/ubuntu/+source/ovn/+bug/1967856 Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Link: https://lore.kernel.org/r/20220606221140.488984-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/openvswitch/actions.c6
-rw-r--r--net/openvswitch/conntrack.c4
2 files changed, 9 insertions, 1 deletions
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 1b5d73079dc9..868db4669a29 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -373,6 +373,7 @@ static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
update_ip_l4_checksum(skb, nh, *addr, new_addr);
csum_replace4(&nh->check, *addr, new_addr);
skb_clear_hash(skb);
+ ovs_ct_clear(skb, NULL);
*addr = new_addr;
}
@@ -420,6 +421,7 @@ static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
update_ipv6_checksum(skb, l4_proto, addr, new_addr);
skb_clear_hash(skb);
+ ovs_ct_clear(skb, NULL);
memcpy(addr, new_addr, sizeof(__be32[4]));
}
@@ -660,6 +662,7 @@ static int set_nsh(struct sk_buff *skb, struct sw_flow_key *flow_key,
static void set_tp_port(struct sk_buff *skb, __be16 *port,
__be16 new_port, __sum16 *check)
{
+ ovs_ct_clear(skb, NULL);
inet_proto_csum_replace2(check, skb, *port, new_port, false);
*port = new_port;
}
@@ -699,6 +702,7 @@ static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
uh->dest = dst;
flow_key->tp.src = src;
flow_key->tp.dst = dst;
+ ovs_ct_clear(skb, NULL);
}
skb_clear_hash(skb);
@@ -761,6 +765,8 @@ static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
skb_clear_hash(skb);
+ ovs_ct_clear(skb, NULL);
+
flow_key->tp.src = sh->source;
flow_key->tp.dst = sh->dest;
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 4a947c13c813..4e70df91d0f2 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1342,7 +1342,9 @@ int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
nf_ct_put(ct);
nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
- ovs_ct_fill_key(skb, key, false);
+
+ if (key)
+ ovs_ct_fill_key(skb, key, false);
return 0;
}