syzbot

kernel msg: ebtables bug: please report to author: Couldn't copy entries from userspace
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refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 22861 at lib/refcount.c:153 refcount_inc+0x5d/0x70 lib/refcount.c:153
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 22861 Comm: syz-executor3 Not tainted 4.18.0-rc8+ #180
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 panic+0x238/0x4e7 kernel/panic.c:184
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:refcount_inc+0x5d/0x70 lib/refcount.c:153
Code: 1d 4d ef 25 05 31 ff 89 de e8 7f b0 1c fe 84 db 75 df e8 a6 af 1c fe 48 c7 c7 40 4b 3a 87 c6 05 2d ef 25 05 01 e8 83 c8 e7 fd <0f> 0b eb c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 
RSP: 0018:ffff8801cac2ee00 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90005638000
RDX: 000000000000347e RSI: ffffffff81632481 RDI: ffff8801cac2ead8
RBP: ffff8801cac2ee08 R08: ffff8801ca27c280 R09: 0000000000000002
R10: ffff8801ca27c280 R11: 0000000000000000 R12: ffff8801c5ea8e40
R13: 000000005b6a4e51 R14: 000000005b6a4e51 R15: ffff8801d787bf50
 sock_hold include/net/sock.h:627 [inline]
 tcp_twsk_unique+0x6a5/0x7f0 net/ipv4/tcp_ipv4.c:177
 twsk_unique include/net/timewait_sock.h:30 [inline]
 __inet6_check_established+0x757/0x1210 net/ipv6/inet6_hashtables.c:274
 __inet_hash_connect+0x363/0xfc0 net/ipv4/inet_hashtables.c:686
 inet6_hash_connect+0x76/0xe0 net/ipv6/inet6_hashtables.c:325
 tcp_v6_connect+0x1838/0x2970 net/ipv6/tcp_ipv6.c:299
 __inet_stream_connect+0x964/0x1150 net/ipv4/af_inet.c:655
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1162 [inline]
 tcp_sendmsg_locked+0x2842/0x3e80 net/ipv4/tcp.c:1209
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1447
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:642 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:652
 __sys_sendto+0x3d7/0x670 net/socket.c:1798
 __do_sys_sendto net/socket.c:1810 [inline]
 __se_sys_sendto net/socket.c:1806 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1806
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456cb9
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fe2db54fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe2db5506d4 RCX: 0000000000456cb9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000017
RBP: 00000000009300a0 R08: 0000000020000040 R09: 000000000000001c
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d38a0 R14: 00000000004c852f R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..