kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 20171 Comm: syz-executor4 Not tainted 4.14.0-rc7-next-20171103+ #10
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff8800217f0100 task.stack: ffff88003c258000
RIP: 0010:__list_del_entry_valid+0x7e/0x150 lib/list_debug.c:51
RSP: 0018:ffff88003c25fb38 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88002d734ad8 RDI: ffff88002d734ae0
RBP: ffff88003c25fb50 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff8744cca0 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff1000784bf8b R15: ffff88002d734ad8
FS:  00007f9e1e850700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004c7964 CR3: 00000000396bc000 CR4: 00000000000006f0
DR0: 0000000020000008 DR1: 0000000020001000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 unregister_shrinker+0x79/0x300 mm/vmscan.c:301
 deactivate_locked_super+0x64/0xd0 fs/super.c:308
 deactivate_super+0x141/0x1b0 fs/super.c:340
 cleanup_mnt+0xb2/0x150 fs/namespace.c:1173
 __cleanup_mnt+0x16/0x20 fs/namespace.c:1180
 task_work_run+0x199/0x270 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath+0x42f/0x510 arch/x86/entry/common.c:266
 entry_SYSCALL_64_fastpath+0xbc/0xbe
RIP: 0033:0x447c89
RSP: 002b:00007f9e1e84fbd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffff RBX: 00007f9e1e8506cc RCX: 0000000000447c89
RDX: 00000000204b2000 RSI: 00000000205d6000 RDI: 0000000020622000
RBP: 0000000000748020 R08: 0000000020a9dfff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000000055e0 R14: 00000000006e9680 R15: 0000000000000002
Code: 00 00 00 00 ad de 49 39 c4 74 66 48 b8 00 02 00 00 00 00 ad de 48 89 da 48 39 c3 74 65 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df <80> 3c 02 00 75 7b 48 8b 13 48 39 f2 75 57 49 8d 7c 24 08 48 b8 
RIP: __list_del_entry_valid+0x7e/0x150 lib/list_debug.c:51 RSP: ffff88003c25fb38
---[ end trace c47b6a901a35c611 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..