syzbot

netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'.
netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'.
refcount_t: saturated; leaking memory.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 15197 at lib/refcount.c:77 refcount_add_not_zero+0x198/0x200 lib/refcount.c:77
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 15197 Comm: syz-executor0 Not tainted 4.14.0-rc7+ #158
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x417 kernel/panic.c:181
 __warn+0x1c4/0x1d9 kernel/panic.c:542
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:refcount_add_not_zero+0x198/0x200 lib/refcount.c:77
RSP: 0018:ffff8801d8c56948 EFLAGS: 00010286
RAX: 0000000000000026 RBX: 0000000000001401 RCX: 0000000000000000
RDX: 0000000000000026 RSI: ffffffff8158842e RDI: ffffed003b18ad1d
RBP: ffff8801d8c569d8 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8801cd2db5fa R11: 0000000000000000 R12: ffff8801d84accbc
R13: 1ffff1003b18ad2a R14: 00000000ffffffff R15: 00000000fffff54c
 refcount_add+0x1b/0x60 lib/refcount.c:101
 tcp_gso_segment+0x1072/0x1650 net/ipv4/tcp_offload.c:155
 tcp4_gso_segment+0xd4/0x2d0 net/ipv4/tcp_offload.c:51
 inet_gso_segment+0x60c/0x11c0 net/ipv4/af_inet.c:1270
 skb_mac_gso_segment+0x33f/0x660 net/core/dev.c:2720
 __skb_gso_segment+0x35f/0x7f0 net/core/dev.c:2792
 skb_gso_segment include/linux/netdevice.h:3954 [inline]
 ip_finish_output_gso net/ipv4/ip_output.c:269 [inline]
 ip_finish_output+0x8a1/0xd10 net/ipv4/ip_output.c:312
 NF_HOOK_COND include/linux/netfilter.h:238 [inline]
 ip_output+0x1cc/0x860 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:458 [inline]
 ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x8c6/0x18e0 net/ipv4/ip_output.c:504
 tcp_transmit_skb+0x19a1/0x3450 net/ipv4/tcp_output.c:1125
 tcp_write_xmit+0x609/0x49a0 net/ipv4/tcp_output.c:2313
 tcp_push_one+0xb5/0xe0 net/ipv4/tcp_output.c:2502
 tcp_sendmsg_locked+0x1d6a/0x3bc0 net/ipv4/tcp.c:1388
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1445
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 ___sys_sendmsg+0x31c/0x890 net/socket.c:2049
 __sys_sendmmsg+0x1e6/0x5f0 net/socket.c:2139
 SYSC_sendmmsg net/socket.c:2170 [inline]
 SyS_sendmmsg+0x35/0x60 net/socket.c:2165
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x452869
RSP: 002b:00007f22424a4be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452869
RDX: 0000000000000001 RSI: 0000000020c0de5c RDI: 0000000000000014
RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000004000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a6f7ff R14: 00007f22424a59c0 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..