A WARN_ON call trace would be triggered when 'ct(commit, alg=helper)'
applies on a confirmed connection:
WARNING: CPU: 0 PID: 1251 at net/netfilter/nf_conntrack_extend.c:98
RIP: 0010:nf_ct_ext_add+0x12d/0x150 [nf_conntrack]
Call Trace:
<TASK>
nf_ct_helper_ext_add+0x12/0x60 [nf_conntrack]
__nf_ct_try_assign_helper+0xc4/0x160 [nf_conntrack]
__ovs_ct_lookup+0x72e/0x780 [openvswitch]
ovs_ct_execute+0x1d8/0x920 [openvswitch]
do_execute_actions+0x4e6/0xb60 [openvswitch]
ovs_execute_actions+0x60/0x140 [openvswitch]
ovs_packet_cmd_execute+0x2ad/0x310 [openvswitch]
genl_family_rcv_msg_doit.isra.15+0x113/0x150
genl_rcv_msg+0xef/0x1f0
which can be reproduced with these OVS flows:
table=0, in_port=veth1,tcp,tcp_dst=2121,ct_state=-trk
actions=ct(commit, table=1)
table=1, in_port=veth1,tcp,tcp_dst=2121,ct_state=+trk+new
actions=ct(commit, alg=ftp),normal
The issue was introduced by commit 248d45f1e1 ("openvswitch: Allow
attaching helper in later commit") where it somehow removed the check
of nf_ct_is_confirmed before asigning the helper. This patch is to fix
it by bringing it back.
Fixes: 248d45f1e1 ("openvswitch: Allow attaching helper in later commit")
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Tested-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/c5c9092a22a2194650222bffaf786902613deb16.1665085502.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>