WARNING: CPU: 0 PID: 25936 at fs/userfaultfd.c:1569 userfaultfd_unregister fs/userfaultfd.c:1569 [inline]
WARNING: CPU: 0 PID: 25936 at fs/userfaultfd.c:1569 userfaultfd_ioctl+0x3d30/0x5610 fs/userfaultfd.c:1845
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 25936 Comm: syz-executor5 Not tainted 4.20.0-rc4+ #261
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+0x244/0x39d lib/dump_stack.c:113
kobject: 'loop1' (00000000a7c0c104): kobject_uevent_env
kobject: 'loop1' (00000000a7c0c104): fill_kobj_path: path = '/devices/virtual/block/loop1'
 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:969
RIP: 0010:userfaultfd_unregister fs/userfaultfd.c:1569 [inline]
RIP: 0010:userfaultfd_ioctl+0x3d30/0x5610 fs/userfaultfd.c:1845
kobject: 'loop4' (000000006cfe1862): kobject_uevent_env
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 4a 60 db ff e9 92 fa ff ff e8 20 07 98 ff <0f> 0b e9 cd f7 ff ff e8 14 07 98 ff 48 8b 95 f0 f6 ff ff b9 01 00
RSP: 0018:ffff88818402f3d0 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 00000000080000d0 RCX: ffffc9000fe72000
RDX: 0000000000000093 RSI: ffffffff81e783b0 RDI: 0000000000000007
RBP: ffff88818402fd60 R08: ffff8881c0a50700 R09: ffff8881c0a50b38
kobject: 'loop4' (000000006cfe1862): fill_kobj_path: path = '/devices/virtual/block/loop4'
R10: ffffed103814a16a R11: ffff8881c0a50b57 R12: 0000000020011000
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8881b86f7a90
kobject: 'input9' (000000001591b4b9): kobject_cleanup, parent           (null)
kobject: 'input9' (000000001591b4b9): calling ktype release
kobject: 'input9': free name
kobject: 'loop2' (00000000c3416ab6): kobject_uevent_env
kobject: 'loop2' (00000000c3416ab6): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop4' (000000006cfe1862): kobject_uevent_env
kobject: 'loop4' (000000006cfe1862): fill_kobj_path: path = '/devices/virtual/block/loop4'
 __do_compat_sys_ioctl fs/compat_ioctl.c:1052 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:998 [inline]
 __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:998
kobject: 'loop2' (00000000c3416ab6): kobject_uevent_env
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
kobject: 'loop2' (00000000c3416ab6): fill_kobj_path: path = '/devices/virtual/block/loop2'
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f5ca29
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5f580cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000008010aa01
kobject: 'loop2' (00000000c3416ab6): kobject_uevent_env
RDX: 0000000020d62fe0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..