overlayfs: conflicting lowerdir path
------------[ cut here ]------------
ODEBUG: free active (active state 1) object type: rcu_head hint:           (null)
kobject: 'loop4' (00000000725e9370): kobject_uevent_env
WARNING: CPU: 0 PID: 8078 at lib/debugobjects.c:325 debug_print_object+0x168/0x250 lib/debugobjects.c:325
kobject: 'loop4' (00000000725e9370): fill_kobj_path: path = '/devices/virtual/block/loop4'
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 8078 Comm: syz-executor.5 Not tainted 4.19.75 #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+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x263/0x507 kernel/panic.c:185
 __warn.cold+0x20/0x4a kernel/panic.c:540
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x204/0x360 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1037
RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:325
Code: dd 20 56 82 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 20 56 82 87 48 c7 c7 60 4b 82 87 e8 d6 04 19 fe <0f> 0b 83 05 cb 83 17 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3
RSP: 0018:ffff888050f9f6f8 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 000000000002ffd8 RSI: ffffffff8155dbd6 RDI: ffffed100a1f3ed1
RBP: ffff888050f9f738 R08: ffff88807f9ee140 R09: ffffed1015d03ee3
R10: ffffed1015d03ee2 R11: ffff8880ae81f717 R12: 0000000000000001
R13: ffffffff8879f200 R14: 0000000000000000 R15: ffff888050a41360
 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline]
 debug_check_no_obj_freed+0x29f/0x464 lib/debugobjects.c:817
 kmem_cache_free+0x18f/0x260 mm/slab.c:3764
kobject: 'loop2' (000000007b23db23): kobject_uevent_env
 free_task_struct kernel/fork.c:162 [inline]
 free_task+0xdd/0x120 kernel/fork.c:416
 __put_task_struct+0x20f/0x4c0 kernel/fork.c:689
 put_task_struct include/linux/sched/task.h:96 [inline]
 finish_task_switch+0x52b/0x780 kernel/sched/core.c:2710
kobject: 'loop2' (000000007b23db23): fill_kobj_path: path = '/devices/virtual/block/loop2'
 context_switch kernel/sched/core.c:2829 [inline]
 __schedule+0x86e/0x1dc0 kernel/sched/core.c:3474
 schedule+0x92/0x1c0 kernel/sched/core.c:3518
 freezable_schedule include/linux/freezer.h:172 [inline]
 futex_wait_queue_me+0x30c/0x600 kernel/futex.c:2607
 futex_wait+0x228/0x5e0 kernel/futex.c:2722
 do_futex+0x175/0x1d70 kernel/futex.c:3646
 __do_sys_futex kernel/futex.c:3707 [inline]
 __se_sys_futex kernel/futex.c:3675 [inline]
 __x64_sys_futex+0x400/0x590 kernel/futex.c:3675
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a29
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc950cf1cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 000000000075bfd0 RCX: 0000000000459a29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075bfd0
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bfd4
R13: 00007ffd923cb7af R14: 00007fc950cf29c0 R15: 000000000075bfd4

======================================================