Cannot find add_set index 0 as target
------------[ cut here ]------------
proc_dir_entry 'ipt_CLUSTERIP/0.0.0.7' already registered
WARNING: CPU: 1 PID: 9418 at fs/proc/generic.c:330 proc_register+0x2d6/0x3b0 fs/proc/generic.c:329
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 9418 Comm: syz-executor6 Not tainted 4.16.0-rc1+ #315
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1dc/0x200 kernel/panic.c:547
 report_bug+0x211/0x2d0 lib/bug.c:184
 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
 fixup_bug arch/x86/kernel/traps.c:247 [inline]
 do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x58/0x80 arch/x86/entry/entry_64.S:957
RIP: 0010:proc_register+0x2d6/0x3b0 fs/proc/generic.c:329
RSP: 0018:ffff8801b8d87360 EFLAGS: 00010286
RAX: dffffc0000000008 RBX: ffff8801b6d733d0 RCX: ffffffff815abdbe
RDX: 0000000000003ff2 RSI: ffffc90006357000 RDI: 1ffff100371b0df1
RBP: ffff8801b8d873b8 R08: 1ffff100371b0db3 R09: 0000000000000000
R10: ffff8801b8d87218 R11: 0000000000000000 R12: ffff8801af35e580
R13: dffffc0000000000 R14: ffff8801d00bda20 R15: ffff8801af35e63b
 proc_create_data+0xf8/0x180 fs/proc/generic.c:494
 clusterip_config_init net/ipv4/netfilter/ipt_CLUSTERIP.c:250 [inline]
 clusterip_tg_check+0xf9c/0x16d0 net/ipv4/netfilter/ipt_CLUSTERIP.c:488
 xt_check_target+0x22c/0x7d0 net/netfilter/x_tables.c:850
 check_target net/ipv4/netfilter/ip_tables.c:513 [inline]
 find_check_entry.isra.8+0x8c8/0xcb0 net/ipv4/netfilter/ip_tables.c:554
 translate_table+0xed1/0x1610 net/ipv4/netfilter/ip_tables.c:725
 do_replace net/ipv4/netfilter/ip_tables.c:1141 [inline]
 do_ipt_set_ctl+0x370/0x5f0 net/ipv4/netfilter/ip_tables.c:1675
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
 ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1259
 udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2401
 ipv6_setsockopt+0xa0/0x130 net/ipv6/ipv6_sockglue.c:917
 tcp_setsockopt+0x82/0xd0 net/ipv4/tcp.c:2905
 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
 SYSC_setsockopt net/socket.c:1849 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1828
 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453a59
RSP: 002b:00007f8fe8b54c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f8fe8b556d4 RCX: 0000000000453a59
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000014
RBP: 000000000071c010 R08: 00000000000003a8 R09: 0000000000000000
R10: 00000000200f9c58 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004d5 R14: 00000000006f7498 R15: 0000000000000002
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..