------------[ cut here ]------------
sysfs group 'loop' not found for kobject 'loop0'
WARNING: CPU: 0 PID: 4531 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: 4531 Comm: syz-executor0 Not tainted 4.17.0+ #9
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
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:ffff880157cff730 EFLAGS: 00010286
RAX: 0000000000000030 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff880157cff798 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: ffffffff86575950 R12: ffffffff8aa09f94
R13: 0000000000000000 R14: ffff880080a7ad48 R15: ffff8801ccabe098
 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+0x44/0xa9
RIP: 0033:0x455907
RSP: 002b:0000000000a3eab8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000000455907
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000013
RBP: 0000000000000013 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000001380 R14: 0000000000a3f160 R15: 00000000007024c0
CPU: 1 PID: 12968 Comm: syz-executor2 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
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x87b/0xab0 lib/fault-inject.c:149
 __should_failslab+0x278/0x2a0 mm/failslab.c:32
 should_failslab+0x29/0x70 mm/slab_common.c:1522
 slab_pre_alloc_hook mm/slab.h:423 [inline]
 slab_alloc_node mm/slub.c:2679 [inline]
 slab_alloc mm/slub.c:2761 [inline]
 __kmalloc+0xbe/0x350 mm/slub.c:3812
 kmalloc include/linux/slab.h:517 [inline]
 kzalloc include/linux/slab.h:701 [inline]
 do_shmat+0x8f4/0x1870 ipc/shm.c:1438
 __do_sys_shmat ipc/shm.c:1524 [inline]
 __se_sys_shmat ipc/shm.c:1519 [inline]
 __x64_sys_shmat+0x10b/0x1c0 ipc/shm.c:1519
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a99
RSP: 002b:00007f150a21cc68 EFLAGS: 00000246 ORIG_RAX: 000000000000001e
RAX: ffffffffffffffda RBX: 00007f150a21d6d4 RCX: 0000000000455a99
RDX: 0000000000005000 RSI: 0000000020ffe000 RDI: 00000000001f803c
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000013
R13: 00000000004c18b4 R14: 00000000004d2768 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..