F2FS-fs (loop1): Magic Mismatch, valid(0xf2f52010) - read(0x0)
F2FS-fs (loop1): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop1): Unrecognized mount option "net/snmp6" or missing value
WARNING: CPU: 1 PID: 7023 at net/ipv4/tcp.c:2415 tcp_close+0xf3d/0x12c0 net/ipv4/tcp.c:2415
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 7023 Comm: syz-executor6 Not tainted 4.19.0-rc2-next-20180904+ #55
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:996
RIP: 0010:tcp_close+0xf3d/0x12c0 net/ipv4/tcp.c:2415
Code: ff ff e8 16 91 d5 fb be 07 00 00 00 48 89 df 4c 8d 63 28 e8 75 f1 fe ff 48 89 df e8 1d dc fd ff e9 e6 f6 ff ff e8 f3 90 d5 fb <0f> 0b e9 71 f8 ff ff e8 e7 90 d5 fb be 07 00 00 00 48 89 df e8 4a
RSP: 0018:ffff88018587fa28 EFLAGS: 00010212
RAX: 0000000000040000 RBX: ffff8801c189e040 RCX: ffffc90002e9c000
RDX: 000000000001a1c5 RSI: ffffffff85a7457d RDI: 0000000000000005
RBP: ffff88018587fae8 R08: ffff88018586a640 R09: ffffed0038313c19
R10: ffffed0038313c19 R11: ffff8801c189e0cb R12: ffff8801c189e068
R13: ffff8801c189e0c8 R14: ffff8801c189e052 R15: 0000000000000007
 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428
 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:457
 __sock_release+0xd7/0x250 net/socket.c:580
 sock_close+0x19/0x20 net/socket.c:1140
 __fput+0x3c1/0xa80 fs/file_table.c:279
 ____fput+0x15/0x20 fs/file_table.c:312
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
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:00007fde93e99c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: 0000000000144fb5 RBX: 00007fde93e9a6d4 RCX: 0000000000457099
RDX: ffffffffffffffd6 RSI: 0000000020000100 RDI: 0000000000000005
RBP: 00000000009300a0 R08: 000000002031e000 R09: 000000000000001c
R10: 0000000020000004 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d4cc8 R14: 00000000004c91af R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..