RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b69f7
R13: 00007f7e9e502b48 R14: 00000000004b6a07 R15: 0000000000000000
list_del corruption. prev->next should be ffff8801cecb7138, but was ffff8801d8e088c0
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:53!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 16072 Comm: syz-executor7 Not tainted 4.13.0+ #66
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cb264540 task.stack: ffff8801cecb0000
RIP: 0010:__list_del_entry_valid+0xef/0x150 lib/list_debug.c:51
RSP: 0018:ffff8801cecb6ef8 EFLAGS: 00010282
RAX: 0000000000000054 RBX: ffff8801c537fa80 RCX: 0000000000000000
RDX: 0000000000000054 RSI: ffffffff8159321e RDI: ffffed0039d96dd3
RBP: ffff8801cecb6f10 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8801cecb6dd8 R11: 0000000000000000 R12: ffff8801c537fa80
R13: dffffc0000000000 R14: ffff8801c29e08c0 R15: ffff8801cecb7140
FS:  00007f7e9e524700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000202b2f70 CR3: 00000001d9016000 CR4: 00000000001426f0
Call Trace:
 __list_del_entry include/linux/list.h:116 [inline]
 list_del include/linux/list.h:124 [inline]
 __remove_wait_queue include/linux/wait.h:182 [inline]
 userfaultfd_event_wait_completion+0x519/0x910 fs/userfaultfd.c:569
 dup_fctx fs/userfaultfd.c:665 [inline]
 dup_userfaultfd_complete+0x2de/0x480 fs/userfaultfd.c:673
 dup_mmap kernel/fork.c:716 [inline]
 dup_mm kernel/fork.c:1184 [inline]
 copy_mm+0xde2/0x1247 kernel/fork.c:1238
 copy_process.part.35+0x1ec4/0x4bd0 kernel/fork.c:1744
 copy_process kernel/fork.c:1554 [inline]
 _do_fork+0x1ef/0xfb0 kernel/fork.c:2035
 SYSC_clone kernel/fork.c:2145 [inline]
 SyS_clone+0x37/0x50 kernel/fork.c:2139
 do_syscall_64+0x26c/0x800 arch/x86/entry/common.c:284
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x451e59
RSP: 002b:00007f7e9e523c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 0000000000451e59
RDX: 0000000020f42000 RSI: 000000002050bfff RDI: 0000000000000000
RBP: 0000000000000450 R08: 0000000020ef4ffc R09: 0000000000000000
R10: 0000000020a6bffc R11: 0000000000000216 R12: 00000000004b721f
R13: 00000000ffffffff R14: 0000000000000000 R15: 000000002050bfff
Code: 4c 89 e2 48 c7 c7 c0 a0 fd 84 e8 62 a5 1d ff 0f 0b 48 c7 c7 20 a1 fd 84 e8 54 a5 1d ff 0f 0b 48 c7 c7 80 a1 fd 84 e8 46 a5 1d ff <0f> 0b 48 c7 c7 e0 a1 fd 84 e8 38 a5 1d ff 0f 0b 48 89 df 48 89 
RIP: __list_del_entry_valid+0xef/0x150 lib/list_debug.c:51 RSP: ffff8801cecb6ef8
---[ end trace 36ed4f2f5a2b4de7 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..