WARNING: CPU: 1 PID: 30903 at fs/userfaultfd.c:1569 userfaultfd_unregister fs/userfaultfd.c:1569 [inline]
WARNING: CPU: 1 PID: 30903 at fs/userfaultfd.c:1569 userfaultfd_ioctl+0x3d30/0x5610 fs/userfaultfd.c:1845
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 30903 Comm: syz-executor1 Not tainted 4.20.0-rc6+ #371
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
kobject: 'loop4' (00000000c8e52009): kobject_uevent_env
Call Trace:
kobject: 'loop4' (00000000c8e52009): fill_kobj_path: path = '/devices/virtual/block/loop4'
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 panic+0x2ad/0x55c kernel/panic.c:188
 __warn.cold.8+0x20/0x45 kernel/panic.c:540
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:userfaultfd_unregister fs/userfaultfd.c:1569 [inline]
RIP: 0010:userfaultfd_ioctl+0x3d30/0x5610 fs/userfaultfd.c:1845
Code: 85 c0 f6 ff ff 48 c1 e8 03 42 80 3c 30 00 0f 84 a3 fa ff ff 48 8b bd c0 f6 ff ff e8 aa 64 db ff e9 92 fa ff ff e8 80 ff 97 ff <0f> 0b e9 cd f7 ff ff e8 74 ff 97 ff 48 8b 95 f0 f6 ff ff b9 01 00
RSP: 0018:ffff888185bcf270 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 00000000080000d0 RCX: ffffc90007e06000
RDX: 000000000000009c RSI: ffffffff81e784f0 RDI: 0000000000000007
RBP: ffff888185bcfc00 R08: ffff888180bfc500 R09: ffff888180bfc938
R10: ffffed103017f92a R11: ffff888180bfc957 R12: 0000000020011000
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8881d1d1b318
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457679
Code: fd b3 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fed0b0cfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457679
RDX: 0000000020d62fe0 RSI: 000000008010aa01 RDI: 0000000000000003
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fed0b0d06d4
R13: 00000000004c16fe R14: 00000000004d3298 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..