list_add corruption. prev->next should be next (ffff8801daf26708), but was 0000000000000000. (prev=ffff8801daf26740).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:28!
invalid opcode: 0000 [#1] SMP KASAN
CPU: 1 PID: 4483 Comm: syz-executor2 Not tainted 4.18.0-rc3-next-20180706+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_add_valid.cold.0+0x23/0x25 lib/list_debug.c:26
Code: e8 9f 72 57 fe eb 97 48 89 d9 48 c7 c7 60 80 1a 88 e8 72 b8 ff fd 0f 0b 48 89 f1 48 c7 c7 20 81 1a 88 48 89 de e8 5e b8 ff fd <0f> 0b 4c 89 e2 48 89 de 48 c7 c7 60 82 1a 88 e8 4a b8 ff fd 0f 0b 
RSP: 0018:ffff8801daf079c0 EFLAGS: 00010086
RAX: 0000000000000075 RBX: ffff8801daf26708 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81634381 RDI: 0000000000000001
RBP: ffff8801daf079d8 R08: ffff8801a060e540 R09: ffffed003b5e4fc0
R10: ffffed003b5e4fc0 R11: ffff8801daf27e07 R12: ffff8801daf26740
R13: ffff8801daf07ab8 R14: ffff8801daf26740 R15: 0000000000000001
FS:  000000000229d940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000706194 CR3: 00000001a05e6000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __list_add include/linux/list.h:60 [inline]
 list_add_tail include/linux/list.h:93 [inline]
 __cpu_stop_queue_work kernel/stop_machine.c:72 [inline]
 cpu_stop_queue_work+0x248/0x460 kernel/stop_machine.c:87
 stop_one_cpu_nowait+0xd3/0x100 kernel/stop_machine.c:341
 watchdog_timer_fn+0x93/0x2e0 kernel/watchdog.c:367
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:867
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:group_pin_kill+0xa8/0x290 fs/fs_pin.c:96
Code: 4c 89 e8 48 c1 e8 03 48 89 85 70 ff ff ff eb 4f e8 fd a8 a6 ff 48 8b 85 70 ff ff ff c6 03 00 42 80 3c 20 00 0f 85 bd 01 00 00 <80> 3b 00 4d 8b 75 00 0f 85 bd 01 00 00 4d 89 77 c0 31 ff 4c 89 f6 
RSP: 0018:ffff8801a06179d0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff100340c2f53 RBX: ffffed00340c2f40 RCX: ffffffff81d5d1ef
RDX: 0000000000000000 RSI: ffffffff81d5d163 RDI: 0000000000000005
RBP: ffff8801a0617a68 R08: ffff8801a060e540 R09: 0000000000000000
R10: ffffed0033f82366 R11: ffff88019fc11b33 R12: dffffc0000000000
R13: ffff8801a0617a98 R14: 0000000000000000 R15: ffff8801a0617a40
 namespace_unlock+0x1c7/0x210 fs/namespace.c:1296
 do_umount fs/namespace.c:1490 [inline]
 ksys_umount+0x849/0x12f0 fs/namespace.c:1585
 __do_sys_umount fs/namespace.c:1596 [inline]
 __se_sys_umount fs/namespace.c:1594 [inline]
 __x64_sys_umount+0x54/0x80 fs/namespace.c:1594
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4585b7
Code: 44 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd 8f fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 dd 8f fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fff085f23f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004585b7
RDX: 000000000229ea13 RSI: 0000000000000002 RDI: 00007fff085f3560
RBP: 00007fff085f3560 R08: 0000000000000000 R09: 000000000000000c
R10: 0000000000000005 R11: 0000000000000246 R12: 000000000229e940
R13: 0000000000000000 R14: 00007fff085f4c40 R15: 0000000000701140
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace f9ebf8b31a88db01 ]---
RIP: 0010:__list_add_valid.cold.0+0x23/0x25 lib/list_debug.c:26
Code: e8 9f 72 57 fe eb 97 48 89 d9 48 c7 c7 60 80 1a 88 e8 72 b8 ff fd 0f 0b 48 89 f1 48 c7 c7 20 81 1a 88 48 89 de e8 5e b8 ff fd <0f> 0b 4c 89 e2 48 89 de 48 c7 c7 60 82 1a 88 e8 4a b8 ff fd 0f 0b 
RSP: 0018:ffff8801daf079c0 EFLAGS: 00010086
RAX: 0000000000000075 RBX: ffff8801daf26708 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81634381 RDI: 0000000000000001
RBP: ffff8801daf079d8 R08: ffff8801a060e540 R09: ffffed003b5e4fc0
R10: ffffed003b5e4fc0 R11: ffff8801daf27e07 R12: ffff8801daf26740
R13: ffff8801daf07ab8 R14: ffff8801daf26740 R15: 0000000000000001
FS:  000000000229d940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000706194 CR3: 00000001a05e6000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400