WARNING: ODEBUG bug in dentry_free

[syzbot]

Hello,

syzbot hit the following crash on net-next commit
18845557fd6fc1998f2d0d8c30467f86db587529 (Thu Mar 29 20:24:06 2018 +0000)
Merge tag 'wireless-drivers-next-for-davem-2018-03-29' of
git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next
syzbot dashboard link:
https://syzkaller.appspot.com/bug?extid=bb1b0635291b0dab8f48

Unfortunately, I don't have any reproducer for this crash yet.
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=6060503050747904
Kernel config: https://syzkaller.appspot.com/x/.config?id=-37309782588693906
compiler: gcc (GCC) 7.1.1 20170620
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org
vi...@zeniv.linux.org.uk]

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Reported-by: syzbot+bb1b06...@syzkaller.appspotmail.com
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IPVS: set_ctl: invalid protocol: 59 224.0.0.2:20000 lc
------------[ cut here ]------------
IPVS: length: 103 != 24
ODEBUG: free active (active state 1) object type: rcu_head hint:
(null)
WARNING: CPU: 1 PID: 4352 at lib/debugobjects.c:291
debug_print_object+0x166/0x220 lib/debugobjects.c:288
IPVS: length: 103 != 24
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4352 Comm: syz-executor2 Not tainted 4.16.0-rc6+ #286
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
panic+0x1e4/0x41c kernel/panic.c:183
__warn+0x1dc/0x200 kernel/panic.c:547
report_bug+0x1f4/0x2b0 lib/bug.c:186
fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
fixup_bug arch/x86/kernel/traps.c:247 [inline]
do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986
RIP: 0010:debug_print_object+0x166/0x220 lib/debugobjects.c:288
RSP: 0018:ffff8801b0f8f778 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff815b7f7e
RDX: 0000000000000000 RSI: 1ffff100361f1e9f RDI: 0000000000000000
RBP: ffff8801b0f8f7b8 R08: 0000000000000000 R09: 1ffff100361f1e75
R10: ffffed00361f1f1e R11: ffffffff87b3b438 R12: 0000000000000001
R13: ffffffff87b44760 R14: ffffffff86e59540 R15: 0000000000000000
__debug_check_no_obj_freed lib/debugobjects.c:745 [inline]
debug_check_no_obj_freed+0x662/0xf1f lib/debugobjects.c:774
kmem_cache_free+0x24c/0x2a0 mm/slab.c:3742
__d_free fs/dcache.c:266 [inline]
dentry_free+0xcd/0x130 fs/dcache.c:342
__dentry_kill+0x4fe/0x700 fs/dcache.c:589
dentry_kill fs/dcache.c:616 [inline]
dput.part.20+0x6fb/0x830 fs/dcache.c:831
dput+0x1f/0x30 fs/dcache.c:795
__fput+0x51c/0x7e0 fs/file_table.c:227
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x199/0x270 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x40e9f0
RSP: 002b:0000000000a3e368 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000a3e390 RCX: 000000000040e9f0
RDX: 00000000000000e0 RSI: 0000000000a3e730 RDI: 0000000000000013
RBP: 0000000000702000 R08: 0000000000006000 R09: 0000000000004000
R10: 0000000000a3e490 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000013 R14: 0000000000000000 R15: 0000000000702000
Shutting down cpus with NMI
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.