------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 18300 at lib/refcount.c:78 refcount_add_not_zero+0x198/0x200 lib/refcount.c:78
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 18300 Comm: syz-executor0 Not tainted 4.14.0-rc8-mm1+ #21
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+0x40/0x90 arch/x86/kernel/traps.c:177
 do_trap_no_signal arch/x86/kernel/traps.c:211 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:260
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:297
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:310
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:926
RIP: 0010:refcount_add_not_zero+0x198/0x200 lib/refcount.c:78
RSP: 0018:ffff8801d73168e0 EFLAGS: 00010282
RAX: dffffc0000000008 RBX: 0000000000006b01 RCX: ffffffff81599c5e
RDX: 0000000000004844 RSI: ffffc900017e6000 RDI: ffff8801d73165e8
RBP: ffff8801d7316970 R08: 1ffff1003ae62c99 R09: 0000000000000000
R10: ffff8801cee3777a R11: 0000000000000000 R12: ffff8801d31991e4
R13: 1ffff1003ae62d1d R14: 00000000ffffffff R15: 00000000ffffadfc
 refcount_add+0x1b/0x60 lib/refcount.c:102
 tcp_gso_segment+0x10d0/0x16b0 net/ipv4/tcp_offload.c:155
 tcp4_gso_segment+0xd4/0x310 net/ipv4/tcp_offload.c:51
 inet_gso_segment+0x60c/0x11c0 net/ipv4/af_inet.c:1272
 skb_mac_gso_segment+0x33f/0x660 net/core/dev.c:2749
 __skb_gso_segment+0x35f/0x7f0 net/core/dev.c:2821
 skb_gso_segment include/linux/netdevice.h:3993 [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:239 [inline]
 ip_output+0x1cc/0x860 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:460 [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+0x1b0d/0x38b0 net/ipv4/tcp_output.c:1176
 tcp_write_xmit+0x680/0x5190 net/ipv4/tcp_output.c:2384
 tcp_push_one+0xc0/0xf0 net/ipv4/tcp_output.c:2572
 tcp_sendmsg_locked+0x1f7d/0x3b80 net/ipv4/tcp.c:1409
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1466
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763
 sock_sendmsg_nosec net/socket.c:632 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:642
 ___sys_sendmsg+0x75b/0x8a0 net/socket.c:2048
 __sys_sendmsg+0xe5/0x210 net/socket.c:2082
 SYSC_sendmsg net/socket.c:2093 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2089
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452879
RSP: 002b:00007f64b9ad6be8 EFLAGS: 00000212 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879
RDX: 0000000004000086 RSI: 0000000020e5bfc8 RDI: 0000000000000014
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f5140
R13: 00000000ffffffff R14: 00007f64b9ad76d4 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..