"Interface can't change network namespaces" is rather an attribute,
not a feature, and it can't be changed via Ethtool.
Make it a "cold" private flag instead of a netdev_feature and free
one more bit.
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
NETIF_F_LLTX can't be changed via Ethtool and is not a feature,
rather an attribute, very similar to IFF_NO_QUEUE (and hot).
Free one netdev_features_t bit and make it a "hot" private flag.
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
<tldr>
skb network header of the single-tagged vlan packet continues to point the
vlan payload (e.g. IP) after second vlan tag is pushed by tc act_vlan. This
causes problem at the dissector which expects double-tagged packet network
header to point to the inner vlan.
The fix is to adjust network header in tcf_act_vlan.c but requires
refactoring of skb_vlan_push function.
</tldr>
Consider the following shell script snippet configuring TC rules on the
veth interface:
ip link add veth0 type veth peer veth1
ip link set veth0 up
ip link set veth1 up
tc qdisc add dev veth0 clsact
tc filter add dev veth0 ingress pref 10 chain 0 flower \
num_of_vlans 2 cvlan_ethtype 0x800 action goto chain 5
tc filter add dev veth0 ingress pref 20 chain 0 flower \
num_of_vlans 1 action vlan push id 100 \
protocol 0x8100 action goto chain 5
tc filter add dev veth0 ingress pref 30 chain 5 flower \
num_of_vlans 2 cvlan_ethtype 0x800 action simple sdata "success"
Sending double-tagged vlan packet with the IP payload inside:
cat <<ENDS | text2pcap - - | tcpreplay -i veth1 -
0000 00 00 00 00 00 11 00 00 00 00 00 22 81 00 00 64 ..........."...d
0010 81 00 00 14 08 00 45 04 00 26 04 d2 00 00 7f 11 ......E..&......
0020 18 ef 0a 00 00 01 14 00 00 02 00 00 00 00 00 12 ................
0030 e1 c7 00 00 00 00 00 00 00 00 00 00 ............
ENDS
will match rule 10, goto rule 30 in chain 5 and correctly emit "success" to
the dmesg.
OTOH, sending single-tagged vlan packet:
cat <<ENDS | text2pcap - - | tcpreplay -i veth1 -
0000 00 00 00 00 00 11 00 00 00 00 00 22 81 00 00 14 ..........."....
0010 08 00 45 04 00 2a 04 d2 00 00 7f 11 18 eb 0a 00 ..E..*..........
0020 00 01 14 00 00 02 00 00 00 00 00 16 e1 bf 00 00 ................
0030 00 00 00 00 00 00 00 00 00 00 00 00 ............
ENDS
will match rule 20, will push the second vlan tag but will *not* match
rule 30. IOW, the match at rule 30 fails if the second vlan was freshly
pushed by the kernel.
Lets look at __skb_flow_dissect working on the double-tagged vlan packet.
Here is the relevant code from around net/core/flow_dissector.c:1277
copy-pasted here for convenience:
if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
skb && skb_vlan_tag_present(skb)) {
proto = skb->protocol;
} else {
vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
data, hlen, &_vlan);
if (!vlan) {
fdret = FLOW_DISSECT_RET_OUT_BAD;
break;
}
proto = vlan->h_vlan_encapsulated_proto;
nhoff += sizeof(*vlan);
}
The "else" clause above gets the protocol of the encapsulated packet from
the skb data at the network header location. printk debugging has showed
that in the good double-tagged packet case proto is
htons(0x800 == ETH_P_IP) as expected. However in the single-tagged packet
case proto is garbage leading to the failure to match tc filter 30.
proto is being set from the skb header pointed by nhoff parameter which is
defined at the beginning of __skb_flow_dissect
(net/core/flow_dissector.c:1055 in the current version):
nhoff = skb_network_offset(skb);
Therefore the culprit seems to be that the skb network offset is different
between double-tagged packet received from the interface and single-tagged
packet having its vlan tag pushed by TC.
Lets look at the interesting points of the lifetime of the single/double
tagged packets as they traverse our packet flow.
Both of them will start at __netif_receive_skb_core where the first vlan
tag will be stripped:
if (eth_type_vlan(skb->protocol)) {
skb = skb_vlan_untag(skb);
if (unlikely(!skb))
goto out;
}
At this stage in double-tagged case skb->data points to the second vlan tag
while in single-tagged case skb->data points to the network (eg. IP)
header.
Looking at TC vlan push action (net/sched/act_vlan.c) we have the following
code at tcf_vlan_act (interesting points are in square brackets):
if (skb_at_tc_ingress(skb))
[1] skb_push_rcsum(skb, skb->mac_len);
....
case TCA_VLAN_ACT_PUSH:
err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
(p->tcfv_push_prio << VLAN_PRIO_SHIFT),
0);
if (err)
goto drop;
break;
....
out:
if (skb_at_tc_ingress(skb))
[3] skb_pull_rcsum(skb, skb->mac_len);
And skb_vlan_push (net/core/skbuff.c:6204) function does:
err = __vlan_insert_tag(skb, skb->vlan_proto,
skb_vlan_tag_get(skb));
if (err)
return err;
skb->protocol = skb->vlan_proto;
[2] skb->mac_len += VLAN_HLEN;
in the case of pushing the second tag. Lets look at what happens with
skb->data of the single-tagged packet at each of the above points:
1. As a result of the skb_push_rcsum, skb->data is moved back to the start
of the packet.
2. First VLAN tag is moved from the skb into packet buffer, skb->mac_len is
incremented, skb->data still points to the start of the packet.
3. As a result of the skb_pull_rcsum, skb->data is moved forward by the
modified skb->mac_len, thus pointing to the network header again.
Then __skb_flow_dissect will get confused by having double-tagged vlan
packet with the skb->data at the network header.
The solution for the bug is to preserve "skb->data at second vlan header"
semantics in the skb_vlan_push function. We do this by manipulating
skb->network_header rather than skb->mac_len. skb_vlan_push callers are
updated to do skb_reset_mac_len.
Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following batch contains Netfilter updates for net-next:
Patch #1 fix checksum calculation in nfnetlink_queue with SCTP,
segment GSO packet since skb_zerocopy() does not support
GSO_BY_FRAGS, from Antonio Ojea.
Patch #2 extend nfnetlink_queue coverage to handle SCTP packets,
from Antonio Ojea.
Patch #3 uses consume_skb() instead of kfree_skb() in nfnetlink,
from Donald Hunter.
Patch #4 adds a dedicate commit list for sets to speed up
intra-transaction lookups, from Florian Westphal.
Patch #5 skips removal of element from abort path for the pipapo
backend, ditching the shadow copy of this datastructure
is sufficient.
Patch #6 moves nf_ct_netns_get() out of nf_conncount_init() to
let users of conncoiunt decide when to enable conntrack,
this is needed by openvswitch, from Xin Long.
Patch #7 pass context to all nft_parse_register_load() in
preparation for the next patch.
Patches #8 and #9 reject loads from uninitialized registers from
control plane to remove register initialization from
datapath. From Florian Westphal.
* tag 'nf-next-24-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_tables: don't initialize registers in nft_do_chain()
netfilter: nf_tables: allow loads only when register is initialized
netfilter: nf_tables: pass context structure to nft_parse_register_load
netfilter: move nf_ct_netns_get out of nf_conncount_init
netfilter: nf_tables: do not remove elements if set backend implements .abort
netfilter: nf_tables: store new sets in dedicated list
netfilter: nfnetlink: convert kfree_skb to consume_skb
selftests: netfilter: nft_queue.sh: sctp coverage
netfilter: nfnetlink_queue: unbreak SCTP traffic
====================
Link: https://patch.msgid.link/20240822221939.157858-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There is something wrong with ovs_drop_reasons. ovs_drop_reasons[0] is
"OVS_DROP_LAST_ACTION", but OVS_DROP_LAST_ACTION == __OVS_DROP_REASON + 1,
which means that ovs_drop_reasons[1] should be "OVS_DROP_LAST_ACTION".
And as Adrian tested, without the patch, adding flow to drop packets
results in:
drop at: do_execute_actions+0x197/0xb20 [openvsw (0xffffffffc0db6f97)
origin: software
input port ifindex: 8
timestamp: Tue Aug 20 10:19:17 2024 859853461 nsec
protocol: 0x800
length: 98
original length: 98
drop reason: OVS_DROP_ACTION_ERROR
With the patch, the same results in:
drop at: do_execute_actions+0x197/0xb20 [openvsw (0xffffffffc0db6f97)
origin: software
input port ifindex: 8
timestamp: Tue Aug 20 10:16:13 2024 475856608 nsec
protocol: 0x800
length: 98
original length: 98
drop reason: OVS_DROP_LAST_ACTION
Fix this by initializing ovs_drop_reasons with index.
Fixes: 9d802da40b ("net: openvswitch: add last-action drop reason")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Tested-by: Adrian Moreno <amorenoz@redhat.com>
Reviewed-by: Adrian Moreno <amorenoz@redhat.com>
Link: https://patch.msgid.link/20240821123252.186305-1-dongml2@chinatelecom.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch is to move nf_ct_netns_get() out of nf_conncount_init()
and let the consumers of nf_conncount decide if they want to turn
on netfilter conntrack.
It makes nf_conncount more flexible to be used in other places and
avoids netfilter conntrack turned on when using it in openvswitch
conntrack.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Similar to commit 70f06c115b ("sched: act_ct: switch to per-action
label counting"), we should also switch to per-action label counting
in openvswitch conntrack, as Florian suggested.
The difference is that nf_connlabels_get() is called unconditionally
when creating an ct action in ovs_ct_copy_action(). As with these
flows:
table=0,ip,actions=ct(commit,table=1)
table=1,ip,actions=ct(commit,exec(set_field:0xac->ct_label),table=2)
it needs to make sure the label ext is created in the 1st flow before
the ct is committed in ovs_ct_commit(). Otherwise, the warning in
nf_ct_ext_add() when creating the label ext in the 2nd flow will
be triggered:
WARN_ON(nf_ct_is_confirmed(ct));
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/6b9347d5c1a0b364e88d900b29a616c3f8e5b1ca.1723483073.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
At this time, conntrack either returns NF_ACCEPT or NF_DROP.
To improve debuging it would be nice to be able to replace NF_DROP
verdict with NF_DROP_REASON() helper,
This helper releases the skb instantly (so drop_monitor can pinpoint
precise location) and returns NF_STOLEN.
Prepare call sites to deal with this before introducing such changes
in conntrack and nat core.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Aaron Conole <aconole@redhat.om>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
e3f02f32a0 ("ionic: fix kernel panic due to multi-buffer handling")
d9c0420999 ("ionic: Mark error paths in the data path as unlikely")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ilya found a failure in running check-kernel tests with at_groups=144
(144: conntrack - FTP SNAT orig tuple) in OVS repo. After his further
investigation, the root cause is that the labels sent to userspace
for related ct are incorrect.
The labels for unconfirmed related ct should use its master's labels.
However, the changes made in commit 8c8b733208 ("openvswitch: set
IPS_CONFIRMED in tmpl status only when commit is set in conntrack")
led to getting labels from this related ct.
So fix it in ovs_ct_get_labels() by changing to copy labels from its
master ct if it is a unconfirmed related ct. Note that there is no
fix needed for ct->mark, as it was already copied from its master
ct for related ct in init_conntrack().
Fixes: 8c8b733208 ("openvswitch: set IPS_CONFIRMED in tmpl status only when commit is set in conntrack")
Reported-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Tested-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 3e2f544dd8 ("net: get stats64 if device if driver is
configured") moved the callback to dev_get_tstats64() to net core, so,
unless the driver is doing some custom stats collection, it does not
need to set .ndo_get_stats64.
Since this driver is now relying in NETDEV_PCPU_STAT_TSTATS, then, it
doesn't need to set the dev_get_tstats64() generic .ndo_get_stats64
function pointer.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com>
Link: https://lore.kernel.org/r/20240531111552.3209198-2-leitao@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
With commit 34d21de99c ("net: Move {l,t,d}stats allocation to core and
convert veth & vrf"), stats allocation could be done on net core instead
of this driver.
With this new approach, the driver doesn't have to bother with error
handling (allocation failure checking, making sure free happens in the
right spot, etc). This is core responsibility now.
Move openvswitch driver to leverage the core allocation.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240531111552.3209198-1-leitao@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Pull networking fixes from Paolo Abeni:
"Quite smaller than usual. Notably it includes the fix for the unix
regression from the past weeks. The TCP window fix will require some
follow-up, already queued.
Current release - regressions:
- af_unix: fix garbage collection of embryos
Previous releases - regressions:
- af_unix: fix race between GC and receive path
- ipv6: sr: fix missing sk_buff release in seg6_input_core
- tcp: remove 64 KByte limit for initial tp->rcv_wnd value
- eth: r8169: fix rx hangup
- eth: lan966x: remove ptp traps in case the ptp is not enabled
- eth: ixgbe: fix link breakage vs cisco switches
- eth: ice: prevent ethtool from corrupting the channels
Previous releases - always broken:
- openvswitch: set the skbuff pkt_type for proper pmtud support
- tcp: Fix shift-out-of-bounds in dctcp_update_alpha()
Misc:
- a bunch of selftests stabilization patches"
* tag 'net-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (25 commits)
r8169: Fix possible ring buffer corruption on fragmented Tx packets.
idpf: Interpret .set_channels() input differently
ice: Interpret .set_channels() input differently
nfc: nci: Fix handling of zero-length payload packets in nci_rx_work()
net: relax socket state check at accept time.
tcp: remove 64 KByte limit for initial tp->rcv_wnd value
net: ti: icssg_prueth: Fix NULL pointer dereference in prueth_probe()
tls: fix missing memory barrier in tls_init
net: fec: avoid lock evasion when reading pps_enable
Revert "ixgbe: Manual AN-37 for troublesome link partners for X550 SFI"
testing: net-drv: use stats64 for testing
net: mana: Fix the extra HZ in mana_hwc_send_request
net: lan966x: Remove ptp traps in case the ptp is not enabled.
openvswitch: Set the skbuff pkt_type for proper pmtud support.
selftest: af_unix: Make SCM_RIGHTS into OOB data.
af_unix: Fix garbage collection of embryos carrying OOB with SCM_RIGHTS
tcp: Fix shift-out-of-bounds in dctcp_update_alpha().
selftests/net: use tc rule to filter the na packet
ipv6: sr: fix memleak in seg6_hmac_init_algo
af_unix: Update unix_sk(sk)->oob_skb under sk_receive_queue lock.
...
With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.
This means that with:
__string(field, mystring)
Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.
There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:
git grep -l __assign_str | while read a ; do
sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
mv /tmp/test-file $a;
done
I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.
Note, the same updates will need to be done for:
__assign_str_len()
__assign_rel_str()
__assign_rel_str_len()
I tested this with both an allmodconfig and an allyesconfig (build only for both).
[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org> # xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>
Open vSwitch is originally intended to switch at layer 2, only dealing with
Ethernet frames. With the introduction of l3 tunnels support, it crossed
into the realm of needing to care a bit about some routing details when
making forwarding decisions. If an oversized packet would need to be
fragmented during this forwarding decision, there is a chance for pmtu
to get involved and generate a routing exception. This is gated by the
skbuff->pkt_type field.
When a flow is already loaded into the openvswitch module this field is
set up and transitioned properly as a packet moves from one port to
another. In the case that a packet execute is invoked after a flow is
newly installed this field is not properly initialized. This causes the
pmtud mechanism to omit sending the required exception messages across
the tunnel boundary and a second attempt needs to be made to make sure
that the routing exception is properly setup. To fix this, we set the
outgoing packet's pkt_type to PACKET_OUTGOING, since it can only get
to the openvswitch module via a port device or packet command.
Even for bridge ports as users, the pkt_type needs to be reset when
doing the transmit as the packet is truly outgoing and routing needs
to get involved post packet transformations, in the case of
VXLAN/GENEVE/udp-tunnel packets. In general, the pkt_type on output
gets ignored, since we go straight to the driver, but in the case of
tunnel ports they go through IP routing layer.
This issue is periodically encountered in complex setups, such as large
openshift deployments, where multiple sets of tunnel traversal occurs.
A way to recreate this is with the ovn-heater project that can setup
a networking environment which mimics such large deployments. We need
larger environments for this because we need to ensure that flow
misses occur. In these environment, without this patch, we can see:
./ovn_cluster.sh start
podman exec ovn-chassis-1 ip r a 170.168.0.5/32 dev eth1 mtu 1200
podman exec ovn-chassis-1 ip netns exec sw01p1 ip r flush cache
podman exec ovn-chassis-1 ip netns exec sw01p1 \
ping 21.0.0.3 -M do -s 1300 -c2
PING 21.0.0.3 (21.0.0.3) 1300(1328) bytes of data.
From 21.0.0.3 icmp_seq=2 Frag needed and DF set (mtu = 1142)
--- 21.0.0.3 ping statistics ---
...
Using tcpdump, we can also see the expected ICMP FRAG_NEEDED message is not
sent into the server.
With this patch, setting the pkt_type, we see the following:
podman exec ovn-chassis-1 ip netns exec sw01p1 \
ping 21.0.0.3 -M do -s 1300 -c2
PING 21.0.0.3 (21.0.0.3) 1300(1328) bytes of data.
From 21.0.0.3 icmp_seq=1 Frag needed and DF set (mtu = 1222)
ping: local error: message too long, mtu=1222
--- 21.0.0.3 ping statistics ---
...
In this case, the first ping request receives the FRAG_NEEDED message and
a local routing exception is created.
Tested-by: Jaime Caamano <jcaamano@redhat.com>
Reported-at: https://issues.redhat.com/browse/FDP-164
Fixes: 58264848a5 ("openvswitch: Add vxlan tunneling support.")
Signed-off-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/20240516200941.16152-1-aconole@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
OVS_PACKET_CMD_EXECUTE has 3 main attributes:
- OVS_PACKET_ATTR_KEY - Packet metadata in a netlink format.
- OVS_PACKET_ATTR_PACKET - Binary packet content.
- OVS_PACKET_ATTR_ACTIONS - Actions to execute on the packet.
OVS_PACKET_ATTR_KEY is parsed first to populate sw_flow_key structure
with the metadata like conntrack state, input port, recirculation id,
etc. Then the packet itself gets parsed to populate the rest of the
keys from the packet headers.
Whenever the packet parsing code starts parsing the ICMPv6 header, it
first zeroes out fields in the key corresponding to Neighbor Discovery
information even if it is not an ND packet.
It is an 'ipv6.nd' field. However, the 'ipv6' is a union that shares
the space between 'nd' and 'ct_orig' that holds the original tuple
conntrack metadata parsed from the OVS_PACKET_ATTR_KEY.
ND packets should not normally have conntrack state, so it's fine to
share the space, but normal ICMPv6 Echo packets or maybe other types of
ICMPv6 can have the state attached and it should not be overwritten.
The issue results in all but the last 4 bytes of the destination
address being wiped from the original conntrack tuple leading to
incorrect packet matching and potentially executing wrong actions
in case this packet recirculates within the datapath or goes back
to userspace.
ND fields should not be accessed in non-ND packets, so not clearing
them should be fine. Executing memset() only for actual ND packets to
avoid the issue.
Initializing the whole thing before parsing is needed because ND packet
may not contain all the options.
The issue only affects the OVS_PACKET_CMD_EXECUTE path and doesn't
affect packets entering OVS datapath from network interfaces, because
in this case CT metadata is populated from skb after the packet is
already parsed.
Fixes: 9dd7f8907c ("openvswitch: Add original direction conntrack tuple to sw_flow_key.")
Reported-by: Antonin Bas <antonin.bas@broadcom.com>
Closes: https://github.com/openvswitch/ovs-issues/issues/327
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://lore.kernel.org/r/20240509094228.1035477-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since kfree_rcu, which is called in the hlist_for_each_entry_rcu traversal
of ovs_ct_limit_exit, is not part of the RCU read critical section, it
is possible that the RCU grace period will pass during the traversal and
the key will be free.
To prevent this, it should be changed to hlist_for_each_entry_safe.
Fixes: 11efd5cb04 ("openvswitch: Support conntrack zone limit")
Signed-off-by: Hyunwoo Kim <v4bel@theori.io>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/ZiYvzQN/Ry5oeFQW@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
