------------[ cut here ]------------ sysfs group 'loop' not found for kobject 'loop0' WARNING: CPU: 0 PID: 8760 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: 0 PID: 8760 Comm: blkid Not tainted 4.17.0+ #16 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:997 RIP: 0010:sysfs_remove_group+0x1d7/0x5f0 fs/sysfs/group.c:233 RSP: 0018:ffff88011e48f8b8 EFLAGS: 00010282 RAX: 0000000000000030 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: aaaaaaaaaaaab000 RDI: ffffea000040b120 RBP: ffff88011e48f920 R08: 0000000001080020 R09: 0000000000000002 R10: 0000000000000000 R11: ffffffff86576dc0 R12: ffffffff8aa0a304 R13: 0000000000000000 R14: ffff8801d186aa50 R15: ffff88013ca2a618 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 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop arch/x86/entry/common.c:166 [inline] prepare_exit_to_usermode+0x33c/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+0x63/0xe7 RIP: 0033:0x7f7b5c9622b0 RSP: 002b:00007ffda7da44d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f7b5c9622b0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000d8b030 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000005 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..