TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
invalid inflight: 1 state 5 cwnd 10 mss 21845
------------[ cut here ]------------
WARNING: CPU: 0 PID: 13680 at net/ipv4/tcp_output.c:2507 tcp_send_loss_probe.cold+0x83/0xa2 net/ipv4/tcp_output.c:2507
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 13680 Comm: syz-executor.1 Not tainted 4.14.144 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x197 lib/dump_stack.c:53
 panic+0x1f2/0x426 kernel/panic.c:182
 __warn.cold+0x2f/0x36 kernel/panic.c:546
 report_bug+0x216/0x254 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
RIP: 0010:tcp_send_loss_probe.cold+0x83/0xa2 net/ipv4/tcp_output.c:2507
RSP: 0018:ffff8880aee07cb8 EFLAGS: 00010282
RAX: 000000000000002d RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000100 RSI: ffffffff866d10e0 RDI: ffffed1015dc0f8d
RBP: ffff8880aee07ce8 R08: 000000000000002d R09: ffff88808c94aeb0
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888083f5c0c0
R13: 0000000000000001 R14: 0000000000005555 R15: 000000000000000a
 tcp_write_timer_handler+0x4a8/0x7e0 net/ipv4/tcp_timer.c:575
kobject: 'loop3' (ffff8880a4a56260): kobject_uevent_env
 tcp_write_timer+0xd8/0x180 net/ipv4/tcp_timer.c:597
 call_timer_fn+0x161/0x670 kernel/time/timer.c:1279
 expire_timers kernel/time/timer.c:1318 [inline]
 __run_timers kernel/time/timer.c:1634 [inline]
 __run_timers kernel/time/timer.c:1602 [inline]
 run_timer_softirq+0x5b4/0x1570 kernel/time/timer.c:1647
kobject: 'loop3' (ffff8880a4a56260): fill_kobj_path: path = '/devices/virtual/block/loop3'
 __do_softirq+0x244/0x9a0 kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x160/0x1b0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x60 kernel/kcov.c:65
RSP: 0018:ffff88806cba7738 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: ffff88808c94a5c0 RBX: 0000000000000000 RCX: 1ffff110119295c6
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: 0000000000000286
RBP: ffff88806cba7770 R08: ffff88808c94a5c0 R09: 0000000000000001
R10: 0000000000000000 R11: ffff88808c94a5c0 R12: ffffea0001fc6a00
R13: ffffea0001fc6a20 R14: ffffea0001fc6a00 R15: dead000000000100
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
 zap_pte_range mm/memory.c:1342 [inline]
 zap_pmd_range mm/memory.c:1444 [inline]
 zap_pud_range mm/memory.c:1473 [inline]
 zap_p4d_range mm/memory.c:1494 [inline]
 unmap_page_range+0xa2d/0x1770 mm/memory.c:1515
 unmap_single_vma+0x15d/0x2c0 mm/memory.c:1560
 unmap_vmas+0xac/0x170 mm/memory.c:1590
 exit_mmap+0x285/0x4e0 mm/mmap.c:3062
 __mmput kernel/fork.c:935 [inline]
 mmput+0x114/0x440 kernel/fork.c:956
 exit_mm kernel/exit.c:545 [inline]
 do_exit+0x71d/0x2c10 kernel/exit.c:861
 do_group_exit+0x111/0x330 kernel/exit.c:977
 get_signal+0x381/0x1cd0 kernel/signal.c:2409
 do_signal+0x86/0x19a0 arch/x86/kernel/signal.c:814
kobject: 'loop3' (ffff8880a4a56260): kobject_uevent_env
kobject: 'loop3' (ffff8880a4a56260): fill_kobj_path: path = '/devices/virtual/block/loop3'
 exit_to_usermode_loop+0x15c/0x220 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4598e9
RSP: 002b:00007ff2654c2c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffe0 RBX: 0000000000000006 RCX: 00000000004598e9
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies.  Check SNMP counters.
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 000000000075bf20 R08: 0000000020000000 R09: 000000000000001c
R10: 0000000020000004 R11: 0000000000000246 R12: 00007ff2654c36d4
R13: 00000000004c7880 R14: 00000000004dd188 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..