WARNING: ODEBUG bug in netdev_run_todo

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    c0842fbc random32: move the pseudo-random 32-bit definitio..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10d7403a900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=76cacb0fe58c4a1e
dashboard link: https://syzkaller.appspot.com/bug?extid=f9484b345f41843fc9a9
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1733e03a900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f9484b345f41843fc9a9@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x80 arch/x86/include/asm/paravirt.h:770
WARNING: CPU: 0 PID: 6856 at lib/debugobjects.c:488 debug_print_object lib/debugobjects.c:485 [inline]
WARNING: CPU: 0 PID: 6856 at lib/debugobjects.c:488 __debug_check_no_obj_freed lib/debugobjects.c:967 [inline]
WARNING: CPU: 0 PID: 6856 at lib/debugobjects.c:488 debug_check_no_obj_freed+0x45c/0x640 lib/debugobjects.c:998
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 6856 Comm: kworker/u4:0 Not tainted 5.8.0-syzkaller #0
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:77 [inline]
 dump_stack+0x1f0/0x31e lib/dump_stack.c:118
 panic+0x264/0x7a0 kernel/panic.c:231
 __warn+0x227/0x250 kernel/panic.c:600
 report_bug+0x1b1/0x2e0 lib/bug.c:198
 handle_bug+0x42/0x80 arch/x86/kernel/traps.c:235
 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:255
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:547
RIP: 0010:debug_print_object lib/debugobjects.c:485 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:967 [inline]
RIP: 0010:debug_check_no_obj_freed+0x45c/0x640 lib/debugobjects.c:998
Code: 74 08 4c 89 f7 e8 04 ce 12 fe 4d 8b 06 48 c7 c7 5f d3 14 89 48 c7 c6 f6 b1 12 89 48 89 da 89 e9 4d 89 f9 31 c0 e8 94 60 a5 fd <0f> 0b 48 ba 00 00 00 00 00 fc ff df ff 05 0e 8f ec 05 48 8b 5c 24
RSP: 0018:ffffc90001867a10 EFLAGS: 00010046
RAX: 480b12f763965400 RBX: ffffffff8918d390 RCX: ffff8880a7904580
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff815e07c9 R09: ffffed1015d041c3
R10: ffffed1015d041c3 R11: 0000000000000000 R12: ffff888090ed4474
R13: ffffffff8ba62fe0 R14: ffffffff894eeca0 R15: ffffffff814c72d0
 kfree+0xfc/0x220 mm/slab.c:3756
 device_release+0x70/0x1a0 drivers/base/core.c:1575
 kobject_cleanup lib/kobject.c:693 [inline]
 kobject_release lib/kobject.c:722 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x15b/0x220 lib/kobject.c:739
 netdev_run_todo+0xb17/0xc90 net/core/dev.c:9797
 default_device_exit_batch+0x66a/0x6b0 net/core/dev.c:10597
 ops_exit_list net/core/net_namespace.c:189 [inline]
 cleanup_net+0x79c/0xba0 net/core/net_namespace.c:603
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269
 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415
 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches