R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000015
R13: 00000000004be07c R14: 00000000004cc498 R15: 0000000000000001
------------[ cut here ]------------
sysfs group 'loop' not found for kobject 'loop0'
WARNING: CPU: 1 PID: 11208 at fs/sysfs/group.c:235 sysfs_remove_group+0x1d7/0x5f0 fs/sysfs/group.c:233
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 11208 Comm: syz-executor4 Not tainted 4.17.0+ #9
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+0x185/0x1d0 lib/dump_stack.c:113
 panic+0x3d0/0x990 kernel/panic.c:184
 __warn+0x40f/0x580 kernel/panic.c:536
 report_bug+0x72a/0x880 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0x1c1/0x620 arch/x86/kernel/traps.c:298
 do_invalid_op+0x46/0x50 arch/x86/kernel/traps.c:317
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:995
RIP: 0010:sysfs_remove_group+0x1d7/0x5f0 fs/sysfs/group.c:233
RSP: 0018:ffff8800861ef3a8 EFLAGS: 00010282
RAX: 0000000000000030 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff8800861ef410 R08: 0000000000000000 R09: 0000000000000002
R10: 0000000000000000 R11: ffffffff86575950 R12: ffffffff8aa09f94
R13: 0000000000000000 R14: ffff88008dac7be8 R15: ffffffff8b58d000
 loop_sysfs_exit drivers/block/loop.c:820 [inline]
 loop_clr_fd+0x889/0xf70 drivers/block/loop.c:1074
 __lo_release drivers/block/loop.c:1644 [inline]
 lo_release+0x1f3/0x2b0 drivers/block/loop.c:1662
 __blkdev_put+0x8ed/0xc90 fs/block_dev.c:1790
 blkdev_put+0x435/0x570 fs/block_dev.c:1852
 blkdev_close+0xa6/0xf0 fs/block_dev.c:1859
 __fput+0x458/0xa30 fs/file_table.c:209
 ____fput+0x37/0x40 fs/file_table.c:243
 task_work_run+0x22e/0x2b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x110e/0x3930 kernel/exit.c:867
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 get_signal+0x1405/0x1ec0 kernel/signal.c:2482
 do_signal+0xb8/0x1d20 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:162 [inline]
 prepare_exit_to_usermode+0x271/0x3a0 arch/x86/entry/common.c:196
 syscall_return_slowpath+0xe9/0x710 arch/x86/entry/common.c:265
 do_syscall_64+0x1ad/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a99
RSP: 002b:00007f2e1886dce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000072bec0 RCX: 0000000000455a99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bec0
RBP: 000000000072bec0 R08: 0000000000000032 R09: 000000000072bea0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000a3e81f R14: 00007f2e1886e9c0 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..