------------[ cut here ]------------ sysfs group 'loop' not found for kobject 'loop0' WARNING: CPU: 1 PID: 4634 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: 4634 Comm: syz-executor0 Not tainted 4.17.0+ #18 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:999 RIP: 0010:sysfs_remove_group+0x1d7/0x5f0 fs/sysfs/group.c:233 RSP: 0018:ffff88014ce9f730 EFLAGS: 00010286 RAX: 0000000000000030 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: aaaaaaaaaaaab000 RDI: ffffea000040b120 RBP: ffff88014ce9f798 R08: 0000000001080020 R09: 0000000000000002 R10: 0000000000000000 R11: ffffffff86577840 R12: ffffffff8aa0a424 R13: 0000000000000000 R14: ffff88010c2ef178 R15: ffff88016ada4358 loop_sysfs_exit drivers/block/loop.c:820 [inline] loop_clr_fd+0x889/0xf70 drivers/block/loop.c:1074 lo_ioctl+0x38e/0x4450 drivers/block/loop.c:1405 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x2290/0x4f80 block/ioctl.c:601 block_ioctl+0x16f/0x1d0 fs/block_dev.c:1877 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0xcbd/0x24b0 fs/ioctl.c:686 ksys_ioctl fs/ioctl.c:701 [inline] __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x280/0x320 fs/ioctl.c:706 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x455927 RSP: 002b:0000000000a3eab8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000000455927 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000013 RBP: 0000000000000013 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000001380 R14: 0000000000a3f160 R15: 00000000007024c0 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..