WARNING: ODEBUG bug in netdev_freemem

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: fa5941f4 Linux 4.14.114
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=132b2084a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d7780000df8e070e
dashboard link: https://syzkaller.appspot.com/bug?extid=490db2c9bfa1aaba7fbb
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+490db2...@syzkaller.appspotmail.com

bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
ODEBUG: free active (active state 0) object type: timer_list hint:
delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:4828
------------[ cut here ]------------
WARNING: CPU: 1 PID: 22 at lib/debugobjects.c:287
debug_print_object.cold+0xa7/0xdb lib/debugobjects.c:287
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 22 Comm: kworker/u4:1 Not tainted 4.14.114 #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x19c lib/dump_stack.c:53
panic+0x1f2/0x438 kernel/panic.c:182
__warn.cold+0x2f/0x34 kernel/panic.c:546
report_bug+0x216/0x254 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:944
RIP: 0010:debug_print_object.cold+0xa7/0xdb lib/debugobjects.c:287
RSP: 0018:ffff8880a9e4f860 EFLAGS: 00010082
RAX: 0000000000000061 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff869d1e40 RDI: ffffed10153c9f02
RBP: ffff8880a9e4f888 R08: 0000000000000061 R09: 0000000000000000
R10: 0000000000000000 R11: ffff8880a9e425c0 R12: ffffffff866cbc00
R13: ffffffff813d5170 R14: 0000000000000000 R15: ffff8880644f1900
__debug_check_no_obj_freed lib/debugobjects.c:747 [inline]
debug_check_no_obj_freed+0x3f5/0x7b7 lib/debugobjects.c:776
kfree+0xbd/0x270 mm/slab.c:3814
kvfree+0x4d/0x60 mm/util.c:416
netdev_freemem+0x4c/0x60 net/core/dev.c:8033
netdev_release+0x72/0x90 net/core/net-sysfs.c:1497
device_release+0x169/0x1b0 drivers/base/core.c:824
kobject_cleanup lib/kobject.c:646 [inline]
kobject_release lib/kobject.c:675 [inline]
kref_put include/linux/kref.h:70 [inline]
kobject_put.cold+0x26f/0x2ff lib/kobject.c:692
netdev_run_todo+0x57a/0x770 net/core/dev.c:7938
rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:106
default_device_exit_batch+0x32a/0x3d0 net/core/dev.c:8722
ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:145
cleanup_net+0x3ba/0x880 net/core/net_namespace.c:484
process_one_work+0x868/0x1610 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x31c/0x430 kernel/kthread.c:232
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402

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[syzbot]

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